The Irwin Double Ended Phillips Impact Screwdriving Bits are specifically engineered for use in high torque Impact Drivers They are manufactured from heavy-duty high-grade steel and have a 3 times increased bit life compared to standard screwdriver bits The screwdriver bits have precision tip geometry that delivers superior fitment reducing stripping and cam-out They have a Power Groove design for compatibility with the IRWIN® Impact Performance Series™ Magnetic Screw-Hold Attachment These bits feature DoubleLok Technology which ensures that both ends of the bit lock securely in impact drivers and quick-change chucks enabling use of two tips from one bit for added convenience and extended life