Wera 05380382001 851/25 H 5/16'' Square Head Drive Phillips Bits are high quality bits designed for phillips screws. Wera 851/25 H 5/16'' Square Head Drive Phillips ® Bits are designed extra-hard for semi-hard materials. Wera 851/25 H 5/16'' Square Head Drive Phillips ® Bits feature a 5/16'' Square Head Drive.