General Tools 73512 Speed-Chuck Precision Screwdriver Set, 12-Piece Spring-loaded speed-chuck allows blade changes instantly. Precision locking system firmly holds blades in place. Non-peel black oxide blades ensure a precision fit and prevent rust. Packaged in a pocket sized fitted zipper case for secure storage. Pull collar back, insert blade for instant lock-up. Precision engineered 750 Series versa-grip handle for maximum performance