This set includes a 1/4" hex impact magnetic bit holder and a selection of commonly used screwdriver bits. The bit holder is made from chrome vanadium steel and stainless steel, which is correctly hardened and tempered for strength and durability. The screwdriver bits are made from S2 steel and have a shock absorbing torsion design for increased torque performance. Each has a blackened hex shank with a shot blast finish and precision ground tips to prevent cam out and screw damage. There are highly visible laser-etched size markings on the hex shank. Specifically designed for use with cordless impact wrenches. Supplied inside a robust duel-injected plastic case.