1/4, 5/16, 3/8 Convenience: Magnetic nut driver provides convenient pick-up and retention of hex fasteners Efficiency: Lobular design drives along flats to reduce rounding of hex fasteners Precision: Flat edges at hex opening for full contact with flanged hex head screws Performance: Performance-optimized S2 steel construction for extended life Includes: ImpactX 3 Pc. 1-3/4 Magnetic Nut Driver Set Magnetic nut driver provides convenient pick-up and retention of hex fasteners Lobular design drives along flats to reduce rounding of hex fasteners Flat edges at hex opening for full contact with flanged hex head screws Performance-optimized S2 steel construction for extended life Calibrated heat treating process for added durability Manganese Phosphate surface for advanced corrosion resistance Ideal for driving hex head nuts and self-tapping screws in a wide variety of applications For use with high torque impact drivers and driver-drills