The Irwin Impact Screwdriver Bits are specifically designed for use in high torque impact drivers. They are manufactured from heavy-duty, high-grade steel, and have a 3 times longer life compared to standard screwdriver bits.Their precision tip geometry delivers superior fitment, reducing stripping, and cam-out. The bits are Power Groove designed for compatibility with IRWIN Impact Performance Series magnetic screw-hold attachment. Supplied in a moulded ABS resin case.This set contains the following:2 x PH1 screwdriver bits.5 x PH2 screwdriver bits.2 x PH3 screwdriver bits.1 x Bit holder.