Abstract: An adjustable screw driver having an improved structure, and more particularly to an adjustable screw driver with a detachable shank having two different tips, a symmetrically-grooved handle on which a flute is set for disposing a wire spring which is attached to the handle by a screw at one end and associated with a control plate by its other end through an aperture of the plate having a square engaging hole at the center. A piece of restraining board having a cut on its periphery is fixed to the bottom of the handle by screws.

Abstract: A low speed air bleed absorption reduction oil saving device for carburetor characterized in the ability to turn air valve to open automatically in circumstances where the automobile concerned is reducing its speed, going downhill or the carburetor is experiencing a momentous absorption internally such that the rotation speed of the engine remains above 950 RPM, equivalent to a speed in motion that is higher than 25 Kms per hour as executed by the high-speed gear, so as to enable the air to enter the cylinder via the air filter so as to hold down the vacuum absorption so as to prevent overfilling of gasoline into the cylinder thereby achieving the objective of saving of use of gasoline fuels.