SHOCKWAVE Impact Duty 40-Piece Driver Bit Set, Alloy Steel, Engineered Most Durable and Best Fitting Driver Bits, Wear Guard Tip for Increased Wear Resistance and Extended Bit Life, Precise-Fit Custom Machined Tips for Optimal Bit Fit, Optimized Shockzone for Maximum Torque Transfer, Includes Most Common Drive Bit Sizes, Compatible with Impact Drivers and Drill Drivers.