Wera Series 4 840/4 Z Sheet Metal Bit, Hexagon 3 x 50mm blade, 1/4" Drive Features Wera's tough viscous and Hex-Plus design, for hexagon socket screws, 3 x 50mm blade x 1/4"Drive For hexagon bit holders and direct drives For AEG, ARO, Atlas-Copco, Biax, Black & Decker, Bosch, Buckeye-Tools, Chicaco Pneumatic, Cleco, Deprag, Desoutter, Gardner-Denver, Hios (Ferra-Tools), Hitachi, Ingersoll-Rand, Iwema (Fuji Air Tools), Keller, Makita, Mall, Metabo, NPK-Air Tools, Pneutec, Rockwell, Rotor Tool, Skil Tool, Stanley, Thor Power-Tool, Tohnichi, Uryu (UPT-Weiler), Van Dorn, Virax, and Wolf hexagon drives Wera Hex-Plus technology prevents rounding of screw recess and transfers up to 20% more torque Limited Lifetime Warranty, German Engineered