The SHOCKWAVE Impact Duty Magnetic Nut Drivers are engineered with the Most Durable Magnet to withstand heavy duty applications throughout the life of the nut driver. The magnetic nut driver securely holds screws during application set-up providing unyielding bit engagement. Made from heat treated CUSTOM ALLOY76 steel to control hardness for extended bit life. The optimized SHOCK ZONE absorbs peak torque and prevents bit breakage. Our magnetic nut drivers feature a chamfered edge for maximum screw-head engagement while the improved hex geometry allows for the best fit and reduced stripping during use. The nut drivers also feature color-coded bands that aid with selecting the right diameter. Designed for use with bit holders in impact drivers and drill drivers. Includes 1 each: 1/4", 5/16", 3/8", 7/16", 1/2" insert magnetic nut drivers (Standard with C-Ring).