Bit-Box 15 Impaktor PH2. High quality bits for Phillips screws in a practical Bit-Box. Impaktor technology provides extra long life even in extreme conditions. Increased frictional resistance thanks to the coarse diamond particle coating on the bit tip prevents the tool from slipping out of the screw. Particularly suitable for use with conventional impact screwdrivers. 1/4" hexagonal, for holders according to DIN ISO 1173-D 6.3.