Nearly 80% of users are now using impact drivers for fastening tasks. IMPACT performance series bits are designed specifically for impact drivers and the higher torque they produce. Precision tip geometry delivers superior fitment, reducing stripping and cam-out and increasing the life of bit and fasteners. Heavy-duty, cold-forged, high-grade steel withstands high torque. The black oxide finish resists corrosion and increases the life of the bit. Magnetic screw-hold attachment's low-profile collar attaches easily to PowerGroove on bits and holds fasteners securely, reducing wobbling and slip. Molded ABS resin case with metal hinge holds up to rigors of daily use. 2-step easy in / out storage holds bits securely in place until you need them. While they're built for maximum durability and long life with impact tools, they also work perfectly with rotary drills and drivers. Includes Impact Power Bit Magnetic Screw-Hold Attachment (1903524), Impact Power Bit #1PH by 2-inch (1837436), Impact Power Bit #2PH by 2-inch (1837455), Impact Power Bit #3PH by 2-inch (1837434), Impact Power Bit #1SQ by 2-inch (1837469), Impact Power Bit #2SQ by 2-inch (1837477), Impact Power Bit #3SQ by 2-inch (1837486), Impact Power Bit T10 by 2-inch (1837495), Impact Power Bit T15 by 2-inch (1837497), Impact Power Bit T20 by 2-inch (1837499), Impact Power Bit T25 by 2-inch (1837502), Impact Power Bit T30 by 2-inch (1837507), Impact Power Bit 6-8SL by 2-inch (1899862), Impact Power Bit 8-10SL by 2-inch (1899864), Impact Power Bit 10-12SL by 2-inch (1899866), Impact Power Bit #2PH by 4-inch (1837459), Impact Power Bit #2PH by 6-inch (1837461), Impact Power Bit #2SQ by 4-inch (1837482), Impact Power Bit T20 by 3-1/2-inch (1837519), Impact Power Bit T25 by 6-inch (1837529).IRWIN Tools IMPACT Performance Series Fastener Power Bits, 20-Piece Set with Pro Case and Magnetic Screw-Hold Attachment (1903766).