IRWIN Tools IMPACT Performance Series Insert Bit Set, 1-inch length, 10-Piece Pocket Set, 4-Pack (1899931) Built for maximum durability and long life with impact drivers 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 Manufactured with heavy-duty, cold-forged, high-grade steel to withstand high torque output 1/4" quick-change shank is designed to work with impact drivers, and reduces slipping in standard drill chucks