Abstract: A vapor-liquid phase fluid heat transfer module includes: at least one evaporator having a first chamber inside, which containing a first working medium; at least one evaporator tube body having a first end, a second end and a condensation section positioned, the first and second ends communicating with the first chamber of the at least one evaporator to form a loop of the first working medium; at least one heat exchanger having a heat exchange chamber, a first face and a second face for the condensation section of the evaporator tube body to attach to; and at least one heat sink tube body, which communicating with the heat exchange chamber of the at least one heat exchanger and the at least one heat sink to form a loop of the second working medium.

Abstract: A vapor chamber has a first plate, a second plate, at least one ring structure, and a chamber. The first plate and the second plate have holes communicating with each other. The second plate has a cavity portion concaved away from the first plate. The ring structure is in the cavity portion and encloses the holes. The chamber is formed between the first plate and the second plate. A capillary structure layer and a working liquid are in the chamber. Therefore, even when either of the first and second plates is broken by heads of screws mounted through the holes, which are larger and oppress the margins of the holes, or even when either of the first and second plates is broken during forming of the holes via stamping or drilling, the chamber always remain sealed.

Abstract: A plate for a heat exchanger between a first medium and a second medium, the plate being associated with a main plane of extension and a main longitudinal direction and including a first heat transfer surface, extending substantially in parallel to the main plane and arranged to be in contact with the first medium, generally flowing along the first surface in a first flow direction; and a second heat transfer surface, extending substantially in parallel to the main plane and arranged to be in contact with the second medium, generally flowing along the second surface in a second flow direction. The first surface includes protruding ridges defining at least two parallel and open-ended channels extending in the first flow direction. The second surface includes a plurality of protruding dimples arranged in the channels between neighbouring respective pairs of the ridges.

Abstract: A cooling module supporting structure includes a radiator support in which pin holes are formed on opposite sides in a vehicle width direction, and a cooling module in which pins are mounted in a vertical direction such that the pins protrude from the cooling module. In the cooling module supporting structure, each pin is inserted through corresponding one of the pin holes such that the cooling module is supported by the radiator support. In the cooling module supporting structure, at least one pin hole of the pin holes has a shape extending toward a rear side of a vehicle in the vehicle width direction from a position where the pin is inserted in a state where the cooling module is supported by the radiator support.

Abstract: A heat exchanger is provided. The heat exchanger includes a core that receives a plurality of mediums. The heat exchanger includes a manifold. The manifold includes a first end that receives a first medium of the plurality of mediums. The manifold includes a second end that intersects the core at a manifold/core interface. The manifold includes a plurality of individual layers that provide gradual transitions for the first medium from the first end to the second end to reduce or eliminate discontinuities at the manifold/core interface that cause stress to the heat exchanger.

Abstract: The present invention provides an economizer 70 including a plurality of cylindrical heat transfer tubes 71a-71d extending along a crossing direction crossing a flowing direction of combustion gas and disposed at a predetermined disposition interval P along the flowing direction, the combustion gas and fluid flowing in the plurality of heat transfer tubes performing heat exchange, and a swirl preventing section 75 disposed in contact with a downstream side outer circumferential surface 71Aa-71Ad in the flowing direction of each of the plurality of heat transfer tubes 71a-71d and configured to prevent a swirl of the combustion gas from occurring near the downstream side outer circumferential surface 71Aa-71Ad.

Abstract: A dehumidifier drainage system includes a primary drain pan and a secondary drain pan. The primary drain pan is disposed at least partially below an evaporator. The primary drain pan includes one or more raised ribs that are configured to at least partially block air flowing across the primary drain pan as the air flows into the evaporator. The secondary drain pan is disposed at least partially between the evaporator and the primary drain pan. The secondary drain pan includes one or more downspouts. Each downspout is configured to funnel water condensed from the evaporator into an area of the primary drain pan that is at least partially surrounded by one of the raised ribs.

Abstract: An upper receiver and barrel assembly includes an upper receiver, a barrel assembly and a gas piston assembly. An upper receiver housing receives a shotgun shell cartridge and the bolt carrier group includes a bolt carrier, a bolt within the bolt carrier, a firing pin and an ejector pin to expel fired shells. The barrel assembly includes a barrel, a barrel extension and a barrel nut to secure the barrel and barrel extension to the upper receiver housing. The gas piston assembly includes a piston body, a piston end cap and a piston bonnet configured to slidably receive the piston end cap therein. A piston gap is defined between the piston end cap and the bonnet end wall. The barrel defines a gas port fluidly connecting the open bore of the barrel with the piston gap. A biasing member urges the piston toward the bonnet.

Abstract: Improvements to firearms that load cartridges from a magazine and/or a clip are disclosed. Specifically, improvements to slide assemblies and bolt assemblies to depress a cartridge in a magazine and/or a clip are provided. Such improvements include a sloped bottom-facing surface of the slide assembly and/or bolt assembly. The sloped bottom-facing surface is sloped along the length of the portion that contacts a cartridge in the magazine and/or clip when the slide assembly and/or bolt assembly reciprocates.

Abstract: This disclosure describes a device that can removably restrain multiple magazines of bullets for a firearm. A preferred embodiment teaches a main body where the locking plate boss of a magazine can be locked and unlocked on either side of the main body; thereby allowing a user to “attach” two magazines of bullets to his/her firearm, and when one magazine is exhausted of bullets, merely pull that magazine out, flip it over, and insert the second magazine. Several means of locking and unlocking are contemplated, including having a removable drive shaft that can rotate a paddle, additionally providing a drive shaft with a wedge-shaped face, and additionally providing a shaft with a key built into it.

Abstract: A magazine adapter for use in a firearm includes a magazine adapter body configured to be bottom-fed and detachably received within a magazine well on the firearm. The magazine adapter body has a bottom panel, an upwardly extending first panel and an upwardly extending second panel defining a channel therebetween proportioned to slidably receive a magazine therein. The second panel defines a groove configured to engage a firearm magazine catch on the firearm when the magazine adapter body is received within the magazine well. The magazine adapter body may detach from the magazine well when the firearm magazine catch is actuated. The first panel includes an adapter magazine catch configured to releasably engage the magazine when the magazine is received within the magazine adapter channel. A magazine release is coupled to the adapter magazine catch. The adapter magazine catch disengages from the magazine when the magazine release is actuated.

Abstract: A motorized magazine loader for loading cartridges into a magazine includes a powered sorting and lifting wheel rotatable about a horizontal axis of rotation, a vertical gravity fed cartridge chute positioned laterally next to the sorting and lifting wheel, an accumulator portion at a lower end of the chute, and a loading portion comprising a receiver for magazines to be loaded and a pusher mechanism for inserting cartridges into the magazines, all supported and substantially contained by a housing. Optimal and ergonomic arrangement of the components and housing configuration provides a minimal footprint, a reduced volumetric size, easy user access to controls, easy access for loading of cartridges, easy insertion and removal of magazines, high stability during operation, and easy transportability. Control circuitry includes jam mediation means.

Abstract: A firearm magazine loader and method are disclosed herein. The firearm magazine loader, in an embodiment, has a receptacle configured to receive a plurality of ammunition units. The firearm magazine loader also has a body that defines or includes a loading structure. The loading structure is configured to be coupled to a plurality of different types of magazine adapters. Each one of the magazine adapters is configured to be coupled to one of a plurality of different types of firearm magazines.

Abstract: An ammunition management device and method are disclosed herein. The ammunition management device, in an embodiment, includes an ammunition receiver, a first structure configured to receive ammunition units from the ammunition receiver, a guide configured to reposition the ammunition units, and a second structure configured to be coupled to an end of a gun magazine. The ammunition management device also includes a drive member configured to force each one of the ammunition units into the end of the gun magazine.

Abstract: A folding pistol has a frame having slide rails adapted to receive a slide, a grip defining a magazine passage pivotally connected to the frame at a first pivot and having a free end extending away from the first pivot, the grip being movable between an extended position in which the pistol is operable, and a stowed position in which the free end of the grip is adjacent the frame, a forward trigger guard element pivotally connected to the frame at a second pivot, a lower trigger guard element connected to the forward trigger guard element at a third pivot, and the lower trigger guard element connected to the grip at a fourth pivot. The first, second, third, and fourth pivots may be at different locations. There may be a trigger connected to the frame at a selected one of the first, second, third, and fourth pivots.

Abstract: A biased pivoting spent ammunition cartridge case extractor and retainer mechanism for blowback bolt firearms. The mechanism includes a distal arcuate hook shaped and dimensioned to intimately engage and nest into part of the circumferential groove in front of the cartridge rim. The hook remains engaged during blowback extraction of the casing from the chamber, and prior to ejection of the case from the firearm. The hook is formed onto the distal end of a rocking member secured to the bolt by a medial pivot. A compression spring bears against the opposite, proximal end of the rocking member thereby biasing the hook inwardly toward the counterbore seat on the distal end of the bolt into which the base of the case rests during extraction. A direct gas impingement system overcomes the biasing force of the spring to cause the case to be ejected.

Abstract: The present invention relates to a safety device for firearms that enables providing additional safety to the original safety of the weapon itself, such that safety conditions prevail in either of the two systems, the original safety of the weapon or the additional safety device object of the present invention, such that if either of the two is in safe or in locked position, the firearm is in safe or locked position, the safety device for firearms being configured to be implemented in a new firearm or an existing firearm, wherein the invention further relates to a safety method for firearms.

Abstract: A carbon fiber composite reinforced gun barrel and a method for making the same. The composite barrel that includes an interference fit gas block sleeve and machined steel ferrule that seals the gas port provided through the laminate composite reducing the risk of pressure leakage and delamination. The disclosed method of winding a carbon fiber resin composite on a structure, such as a rifle barrel, produces, for a given layer, constant wind angles that are engineered for longitudinal stiffness throughout the length of a given layer. The engineered wind angles throughout the length of each layer of fiber minimizing sacrificial material for the benefit of optimal fiber orientations and wound fiber collation. Whereas the base layers are defined by hoop winding, the orientation angles of successive strata becomes progressively lower and lower until the outermost strata achieve the target orientation angle of approximately 3 to 5 degrees.

Abstract: A firearm suppressor assembly that includes a quick connect mounting methodology that allows the suppressor to be quickly and repeatably associated with the muzzle end of a firearm. In a preferred embodiment, the mounting methodology includes a plurality of lobes that facilitate less than 90 degree rotation between the muzzle of the firearm and the suppressor and provide a tactile indication of a secured engagement therebetween.

Abstract: The present invention relates to a coupling member for quick and easy attachment and detachment of a firearm accessory to a muzzle of the firearm, the coupling member comprising a female member and a male member, wherein the female member is provided with a throughgoing bore, the female member further being provided with a number of successive threaded portions and unthreaded portions around a circumference of the throughgoing bore and wherein the male member around an outer circumference is provided with the same number of successive threaded portions and unthreaded portions as the female member.

Abstract: A rifle comprises a quad lock multicaliber receiver, a barrel extension, a bolt, and a projection engageable with the receiver. The barrel extension includes a cartridge chamber and is securable in an end of the receiver. The bolt is slideable in the receiver and engages a cartridge in the cartridge chamber during the firing phase. The projection comprises locking bars extending through the receiver, and is moveable between locked and unlocked positions to allow for securing and removing of the barrel extension, respectively. Positioning bars are disposed on either side of the receiver split parallel to its longitudinal axis. The locking bars are disposed between these positioning bars and the barrel extension such that when the positioning bars are urged toward each other the receiver split is closed and the positioning bars urge the locking bars toward and into locking grooves to secure the barrel extension in the receiver.

Abstract: A gun transport system is described for safely and securely transporting guns in a bed of a utility vehicle. The gun transport system comprises a support frame that mounts to the sidewalls of the vehicle bed and two or more gun cases that can be releaseably secured to the support frame. The support frame includes two frame sections that are pivotally connected at one end to a sidewall of the vehicle bed and pivotally connected to one another at the opposite end. The three-point pivot arrangement enables the support frame to fit vehicle beds of varying width. The support frame supports the gun cases at an angled position so that the gun cases are easily accessible from the sides of the vehicle and the front end of the gun case pointing upwardly.

Abstract: A firearm system for monitoring the displacement of a firearm trigger during a trigger pull includes a firearm body including a handle and a barrel attached to the handle. A trigger is attached to the firearm body, and a position input circuit is attached to the trigger. The position input circuit emits a trigger position signal including information representative of the trigger displacement. The firearm body is in wired or wireless communication with an electronic device. The electronic device can include a monitor, or screen, for graphically displaying a trigger position indicator representative of the displacement of the trigger along one or more axes. The firearm body can include a motion sensing circuit generally adapted to detect motion of the firearm body. The motion sensing circuit can include one or more accelerometers or gyroscopes.

Abstract: A composite striker for a firearm simulator which employs a firing pin and provides pneumatic recoil. The composite striker including at least a first segment constructed of a material which is softer than the firing pin and at least a second segment being suitable for displacing a valve in order to initiate the pneumatic recoil.

Abstract: An archery bow having an amplifier is described herein, and also described herein is a method for retrofitting archery bows with such an amplifier. The archery bow, in an embodiment, includes an assembly, first and second limbs, a bow string, one or more amplifiers, and an energy resource. The assembly includes a section, and first and second limb supports. The first and second limbs are each configured to at least partially move relative to the section in response to an amplifier force, and the bow string is configured to increase in tension as result of the amplifier force.

Abstract: In some embodiments, a crossbow trigger mechanism comprises a housing, a trigger, a latch and a latch retaining mechanism. The housing defines a slot. The latch comprises a string catch and a trigger engaging portion. The latch is moveable with respect to the housing between first and second positions. In the first position, the trigger engaging portion contacts the trigger. In the second position, the trigger engaging portion does not contact the trigger. The latch retaining mechanism is arranged to retain the latch in the second position.

Abstract: A magazine for a high capacity loader for sequentially loading a plurality of projectiles into a launcher. The magazine has a magazine housing for holding a plurality of projectiles. The magazine housing has an opening providing access to a projectile chimney. The projectiles exit the magazine through the opening in the magazine housing via the projectile chimney. An aperture is provided in a sidewall of the projectile chimney and the aperture leads to a piston chamber. A pneumatically actuated actuator is provided in the piston chamber. The pneumatically actuated actuator drives an indexing assembly for the launcher.

Abstract: Collapsible and extendable buttstock apparatus for use on a weapon having a buffer tube element. The apparatus is assembled onto the buffer tube and tightened in place using a compression clamp to hold the apparatus to the buffer tube. Upon release of the clamp the assembly can be slid along the buffer tube to a desired location and clamped in the preferred position.

Abstract: A pistol chassis is disclosed which may include a lower housing, an upper housing, a proximal enclosure, a distal sleeve, and a proximal accessory. The distal sleeve, lower housing, and upper housing may be secured together to form a tubular member for receiving a pistol. The lower housing further may include a distal segment, a proximal segment and an intermediate segment. Time distal segment may include a pistol frame receptacle and a trigger guard enclosure. The proximal accessory may be a folding stock. The pistol chassis may house a pistol to produce a firearm apparatus.

Abstract: A stabilizing device for a small arms weapon is disclosed. The stabilizing device may include a housing, a starboard side support member, a port side support member, and a primary hinge pin. The primary hinge pin, the starboard side support member, and the port side support member may form a joint. The stabilizing device further may include a webbing. The webbing may include one end secured to the starboard side support member and another end secured to the port side support member. The webbing may form a sling. The sling may be configured and dimensioned to rest on a body disposed between the first base and the second base. The body may be the forearm of an operator grasping the small arms weapon in a single hand. In one embodiment, the stabilizing device for a small arms weapon is connected to a pistol chassis.

Abstract: A handguard attachment assembly for a firearm is disclosed. The assembly includes a handguard with an elongate structure extending between a first end and a second end, where the handguard has at least one opening proximate the first end. A flange insert is received in an opening on a first side of the handguard and engages the handguard. A fastener secures the flange insert to a connector positioned over the barrel nut. The fastener can be tightened to draw the handguard to the barrel nut. The connector can be a bridge connector positioned on or over the barrel nut within the handguard, or can be a connector with a flange portion that engages the second side of the handguard and has a connector body that extends towards the flange insert on the first side, to name a few examples.

Abstract: Holsters have a body defining a pistol receptacle, the body having a medially-facing first major surface configured to face toward a wearer, a laterally-facing second major surface configured to face away from the wearer, a first belt passage associated with the first major surface and adapted to receive a wearer's belt with a portion of the belt between a major portion of the body, a belt loop receptacle associated with the second major surface, a belt loop element configured to be removably received by the belt loop receptacle, the belt loop element including a fastener having a fastened condition and an unfastened condition, and the fastener adapted to secure the belt loop element in a closed loop when in the fastened condition to encompass a wearer's belt with the body between the belt and the wearer, and to enable insertion and removal of a belt when in an unfastened condition.

Abstract: Iron sights for a handgun that positions both the front and rear sight components within the shooter's depth of field when the handgun is presented at extension. In one exemplary embodiment for a pistol, the iron sights of this invention include a front sight component located adjacent the muzzle end of a conventional handgun and a rear sight component located forward of the ejection port of the pistol. The front sight component and rear sight component are spaced apart from one another to have a sight radius of less than two and a half inches, so that the focal planes of both sight components fall within the shooter's field of view when the pistol is presented on target. By positioning the front and rear sight components closer together, against traditional conventions of marksmanship, to be within the shooter's depth of field, both of the front and rear sight components can be clearly perceived visually by the shooter when the handgun is presented at extension on target.

Abstract: A firearm sight system is provided having a mounting rail with an upper surface. The mounting rail defines a pocket below the upper surface. A sight arm is pivotally connected to the rail and movable between an elevated position angularly offset from the upper surface of the rail and a stowed position in which the sight arm occupies the pocket and does not protrude above the upper surface of the rail.

Abstract: A rear sight assembly is disclosed. The rear sight assembly contains a housing defining a first opening, a second opening, and a third opening, a rear sight mechanism containing a thumb wheel positioned in the first opening, at least partially threaded support member positioned in the second opening and the third opening, wherein the at least partially threaded support member is threaded through the thumb wheel, and a rear aiming point member adjustably coupled with the at least partially threaded support member.

Abstract: A laser aiming and illumination device configured to be mounted onto a firearm such that mounting the device onto the firearm does not require permanent alteration of the firearm, the firearm having a trigger, a grip, a lower portion and an upper portion having a side surface. The laser aiming and illumination device includes an illumination module, including at least one of an illumination source and a laser source mounted to the side surface, an illumination mode selector configured to select an operating mode of the at least one of the illumination source and the laser source, a power module including a power source inside the grip, the power module electrically connected to the illumination module, an activation switch disposed adjacent the trigger of the firearm and configured to operate the at least one of the illumination source and the laser source in the selected operating mode.

Abstract: A system and method for scope leveling. The scope has a scope body. The scope body has a leveling indicator. In one example, the leveling indicator is an engraved line which extends longitudinally along the length of the scope. The scope is manipulated such that the leveling indicator is properly aligned relative to a mount. The system and method results in a level scope which reduces canted angles and increases accuracy.

Abstract: A system and method for scope leveling. The scope has a scope body. The scope body has a leveling indicator. In one example, the leveling indicator is an engraved line which extends longitudinally along the length of the scope. The scope is manipulated such that the leveling indicator is properly aligned relative to a mount. The system and method results in a level scope which reduces canted angles and increases accuracy.

Abstract: Before a person can use any weapon, such as a gun or a rifle, effectively, the sight must be aligned to the barrel through a zeroing process. Various embodiments discloses a firearm zeroing app for automatically determining the adjustments of a weapon equipped with an optical sight. The system can utilize a mobile device to take a picture to capture an image of a shot group. Then, using the app, the system automatically calculates the datum of the shot group, the centroid of the shot group, and the distance for adjustment of the sighting device to accurately fire the firearm. In another embodiment, the mobile device can be configured to capture and record the image of firing of the firearm so that the app automatically captures as a video the images of the shots fired to establish the shot group and automatically analyzes the projectile's flight path data.

Abstract: Provided herein are systems and methods for shooting simulation of a target with a projectile. More particularly, the invention relates to virtual reality optical projection systems to monitor and simulate shooting.

Abstract: A system, including a firearm comprising a receiver and an illumination sight. A illumination sight for a firearm that includes a housing member that is configured to be placed over a receiver of a firearm that couplable to a top portion of the receiver, the housing member including a lower extension that extends down the side of the receiver toward a trigger of the firearm when installed, a light source disposed within the housing member, and a power source disposed within the housing member that is configured to power the light source. A firearm that includes a laser sight illumination sight.

Abstract: Communication method and system for bidirectional data transfer among smart modules (101-111) attachable to a weapon (100), where messages are encoded by modulating an electric supply provided by at least one powered rail (200, 200?, 200?, 200??). At least two priority levels are defined among smart modules supplied by the powered rail (200, 200?, 200?, 200??). High-priority smart modules (600) are allowed to transmit high-priority data message (741) directly; whereas low-priority smart modules (500) are required to transmit a data transfer request message (723) and wait for a data transfer permission message (731), which is only sent when no high-priority data message (741) is being received.

Abstract: An adjustable ballistic garment includes a first panel, an opposing second panel, and a connection assembly configured to releasably and adjustably couple the first panel to the second panel. The first panel has a first end of a strap attached thereto, while a second end of the strap is free-hanging. The second panel includes an adjustable tensioning loop and a rotary tensioning knob configured to adjust a length of the tensioning loop. A first coupling member is attached to a second end of the strap and includes a pin extending therefrom. A second coupling member is formed separately from the tensioning loop and the first coupling member and includes a cavity configured to receive the pin of the first coupling member and channel configured to receive the tensioning loop.

Abstract: Body armor plates are provided that can include two opposing and angled wither bends. Methods for manufacturing a body armor plate are provided; the methods can include: providing a substantially unbent plate defining a trapezoid portion sharing one edge with a rectangular portion, the rectangular portion having another edge opposing the one edge; marking the plate with an isosceles triangle, a baseline of the isosceles triangle extending along the one edge shared by the trapezoid portion and the rectangular portion, and the sidelines of the isosceles triangle forming the isosceles triangle vertex at a midpoint of the other edge opposing one edge; and aligning the plate within a press along each of the marked sidelines; and bending the plate along each of the sidelines of the triangle.

Abstract: A seating assembly includes a seat base. A seatback is operably coupled to the seat base and includes a seat cushion disposed on a front side thereof. A protective panel operably coupled with the seatback panel. The protective panel includes an internal aluminum panel disposed inside the seatback. An external aluminum panel is disposed on the seatback. A polymeric matrix is disposed between the internal aluminum panel and the external aluminum panel.

Abstract: An example barrier can be switchable between an at least partially collapsed state and at least partially expanded state (e.g., a deployed state). For example, the barrier can be formed from a continuous sheet and a plurality of rigid sections (e.g., rigid panels) attached or incorporated into the continuous sheet. The barrier can also include a plurality of hinges, such as hinge lines, between the panels that are formed from the continuous sheet. The hinges enable the barrier to be rigid foldable (e.g., the hinges can fold and unfold while the rigid sections remain stiff and rigid) between the expanded and collapsed states.

Abstract: The present invention comprises a novel method for passive wide-area interdiction of small remotely controlled or fully autonomous airborne devices, commonly referred to as drones, whether singular vehicles or in swarms, by deploying a low-cost fouling material into the desired protection zone. The deployed fouling material being light-weight, so as to float through and widely disperse within the airspace over the protected zone, then so designed to physically ensnare or attach itself in a manner to degrade the flying capability or other mission capabilities of the unwanted drones passing through or loitering within the protected airspace. One example, but not the only example, of such embodiment might be dispersal of very fine synthetic spider-silk threads having the characteristic of high-strength combined with kilometer-lengths and a relatively short active state life span, after which naturally and relatively quickly dissolving with any remaining residue being absorbed into the environment.

Abstract: A conducted electrical weapon (“CEW”) impedes locomotion of a human or animal target by providing a stimulus signal through one or more electrodes and through the target. The CEW includes a handle and one or more removable deployment units coupled to the handle. A deployment unit may include guide for positioning a filament.

Abstract: A multi-piece ammunition cartridge casing includes a casing base extending along a central axis and defining an opening extending axially into the casing base from the distal base end. The inner casing surface defines a circumferential groove with a groove radius greater than a radius of an adjacent portion of the opening. The cartridge casing also includes a casing body with a proximal end portion disposed in the opening of the casing base. The casing body is secured to the casing base by way of a flange protruding radially outward in mating contact with the circumferential groove.

Abstract: Muzzleloader systems include a pre-packaged propellant charge with a primer receptacle for providing efficient loading and unloading of the muzzleloader. The muzzleloader accepts in the breech end a propellant containment vessel that abuts against a constriction portion with a reduced diameter portion. The propellant containment vessel having an end portion with a tapered surface that conforms to the constriction portion surface. A projectile is inserted in the muzzle end of the muzzleloader and seats against the constriction portion.