IRWIN Tools IMPACT Performance Series Deep Well Socket Bits, 3/8-inch Square Drive, 10-Piece Set, Rail (1882412) IMPACT performance series bits are designed specifically for impact drivers and the higher torque they produce. 6-point deep wells with recessed corners drive torque across the flats for a more secure fit, eliminating movement and extending the life of the bit. Made with heavy-duty chrome molybdenum steel for maximum durability. The black oxide finish resists corrosion. Thin wall construction allows easy access to tight spaces. Socket size is clearly identified with large, permanent, laser-etched markings. Rail with ball-lock clips offers easy-access storage and attaches to work or storage surfaces securely with rare earth magnets. Non-mar foam backing.