Wera Series 4 851/4 A Special Design Bit, Phillips PH 4 x 50mm Blade Features Wera's Extrahard design, for Phillips screws, PH 4 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 Extra hard bits for soft materials (e.g. wood and general construction materials) are made from a special material that extends the tools' service life and reduces the risk of material damage Limited Lifetime Warranty, German Engineered