Abstract: A heart valve sizer and sizer cover are provided for determining the size of a heart valve annulus. The valve sizer can include a handle, a shaft extending distally from the handle, a sizing element coupled to the distal end of the shaft, the sizing element being movable between a first retracted position and a second expanded position, and a sizer cover. The sizer cover can be formed from a continuous sheet of material configured to surround at least a portion of the sizing element of the heart valve sizer so as to guard against entanglement of the sizing element with structures of a human heart.

Abstract: There is disclosed a motor of a pneumatic tool. The motor includes a cylinder, a rotor put in the cylinder, a plurality of leaves movable to the cylinder from the rotor in operation, a front cover connected to a front end of the cylinder, a rear cover connected to a rear end of the cylinder, a front pad put between the rotor and the front cover and between the leaves and the front cover, and a rear pad put between the rotor and the rear cover and between the leaves and the rear cover.

Abstract: A clutch is disclosed for a power tool. The clutch includes a disc, a drum, at least one spring and at least one pin. The disc defines at least one arched groove comprising a floor and an inclined wall. The drum defines at least one eccentric hole. The spring is put in the eccentric hole. An end of the pin is put in the eccentric hole and pushed by means of the spring. An opposite end of the pin is exposed from the eccentric hole for pushing the inclined wall before a predetermined value of torque is reached and for sliding on the inclined wall after the predetermined value of torque is reached.

Abstract: An aquarium includes a container to receive water and live fish therein, and a hanging unit by which the container is adapted to be hung on a stationary wall. The container includes a vertical rectangular rear wail, a horizontal rectangular bottom wall, two trapezoid side walls, and a downwardly and rearwardly inclined rectangular front wall with a transparent piece fitted sealingly therein. Each of the trapezoid side walls has a vertical rear side coupled with the rear wall, a horizontal bottom side coupled with the bottom wall, a horizontal top side which is longer than the bottom side, and an inclined front side coupled with the front wall. The hanging unit includes two hanging holes formed through the rear wall of the container, and two hooks which extend through the hanging holes to fasten on the stationary wall so as to hang the aquarium on the stationary wall.