Wera 840/1 Z HEX-PLUS SW Bit – 8 x 25mm. Tough Wera bits for hexagonal socket screws for universal use. Hex-Plus offers lager contact surfaces in the screw head. The notch effect is reduced to a minimum and the destruction of the screw is nearly eliminated. 1/4″ hexagonal suitable for holders as per DIN ISO 1173-D 6.3.