While most screwdriving bits are simply compatible with impact drills and drivers, IRWIN Impact Performance Series fastener drive bits are engineered for maximum durability and long life with impact drivers. These bits are forged* rather than milled, so they fit fasteners more precisely, which reduces stripping and increases the life of the bit itself – IRWIN's Impact Performance Series bits have three times longer life than traditional bits. Manufactured with heavy-duty, cold-forged, high-grade steel, they'll withstand extremely high torque output. Plus, a black oxide finish resists corrosion and increases the life of the bit.Built for maximum durability and long life with impact drivers.Forged bit (vs. milled) for superior fitment, which reduces stripping and increases life of bit 3X.*Manufactured with heavy-duty, cold-forged, high-grade steel to withstand high torque output.Black oxide finish resists corrosion and increases life of bit.Two-step easy in / out bit storage holds bits securely in place until ready for useMolded ABS resin case holds up to rigors of daily useFull-length metal pin in hinge for added durability and life*Square and Phillips bits only**vs. standard screwdriver bitsSpecificationsItem #Contents1903768Impact Power Bit Magnetic Screw-Hold Attachment (1903524), Impact Power Bit #2PH X 2" (1837455), Impact Power Bit #3PH X 2" (1837434), Impact Power Bit #2SQ X 2" (1837477), Impact Power Bit T15 X 2" (1837497), Impact Power Bit T20 X 2" (1837499), Impact Power Bit T25 X 2" (1837502), Impact Power Bit T30 X 2" (1837507), Impact Power Bit 6-8SL X 2" (1899862), Impact Power Bit 8-10SL X 2" (1899864), Impact Power Bit #2PH X 4" (1837459), Impact Power Bit #2SQ X 4" (1837482), Impact Power Bit T25 X 3-1/2" (1837521), Impact Nutsetter Lobular Magnetic 1/4" X 1-7/8" (1837535), Impact Nutsetter Lobular Magnetic 5/16" X 1-7/8" (1837538), Impact Nutsetter Lobular Magnetic 3/8" X 1-7/8" (1837541), Impact Nutsetter Lobular Magnetic 7/16" X 1-