A) a handle comprising two handle halves defining a blade slot therebetween;

B) a blade pivotally mounted on a pivot pin extending through the handle at one end of the blade slot, the blade being pivotal between a closed position in which the blade is substantially received in the blade slot and an open position extending from the handle, the blade defining an arcuate pivot slot concentric with the pivot pin, the arcuate pivot slot having an enlarged lock opening at each of the respective ends thereof;

C) a blade lock plunger extending across the blade slot and through the arcuate pivot slot in the blade, the blade plunger having a lock portion sized to be closely accommodated in the lock openings of the arcuate pivot slot, the blade lock plunger and the lock openings being positioned for securing the blade in its closed position and in its open position, the blade lock plunger further comprising a smaller release portion positionable in the arcuate pivot slot by axially shifting the blade lock plunger, the release portion permitting the blade to pivot between its open and closed position, the blade lock plunger being spring biased to position the lock portion of the blade lock plunger in the lock openings of the arcuate pivot slot, and the blade lock plunger having an actuating end extending from the handle for manually axially shifting the blade lock plunger by depressing the actuating end;

D) a pocketed clamp positioned against one of the handle halves and defining an opening receiving the pivot pin and a pocket receiving a coil spring for biasing the blade lock plunger; and

E) an apertured clamp positioned against the other handle half and having an aperture receiving the pivot pin and an aperture permitting the actuating end of the blade lock plunger to extend from the handle for manipulation, wherein the pivot pin secures the pocketed clamp, the handle halves and the apertured clamp together.