Milwaukee 48-32-4512 Shockwave Impact Duty 1/4" Hex Shank Magnetic 12&rdquo; Bit Holder MAGNETIC BIT HOLDING: Keep a firm hold of bits while making them easy to replace with the help of the magnetized end of this bit extension BIT EXTENSION: You will get 12 extra inches in length for your bits, letting you drive into deeper grooves or remove recessed fasteners PROPRIETARY STEEL: This steel blend from Milwaukee will hold up to the rigors of industrial jobsites HEAT TREATING cements the strength of the steel, giving it an improved lifetime compared to bits and accessories that dont undergo this process 2 PIECE CONSTRUCTION: Manufacturing this tool in two sections gives it improved resistance to high-torque applications, letting you use bits for larger fasteners through more hardy materials