IRWIN® Impact Pro Performance Phillips Screwdriver Bits have been engineered for maximum durability and turning force when used in extreme applications. The full fit head eliminates wobble and screw head roundings. With a contoured area, so the bit tip flexes with the torque of the impact driver. Flex optimised to transfer maximum torque through the screw and maximise life. IRWIN Impact Pro Performance Screwdriver Bits, Phillips