IRWIN Tools IMPACT Performance Series Double-Ended Screwdriver Power Bit, Square, 2 3/8-inch length, 5-Piece Set with Magnetic Screw Hold Attachment (1903521) Built for maximum durability and long life with impact drivers. DoubleLokTechnology ensures both ends of bit lock securely Precision tip geometry delivers superior fitment, reducing stripping and cam-out Power Groove designed for compatibility with IRWIN Impact Performance Series Magnetic Screw-Hold Attachment 1/4" quick-change shank is designed to work with impact drivers, and reduces slipping in standard drill chucks