TheGripEdge Tools 16-pc 3/8" Drive Short Metric & SAE Hex Driver Set, No. HB16S, features Rounding Prevention Technology (R.P.T.), and its precision-machined S2 steel bits are designed to deliver up to 50 percent more torque on good fasteners and up to 400 percent more on damaged ones. The set includes sizes from 4mm to 12mm and 1/8" to 3/8". The patented bi-directional geometry prevents rounding, ensuring reliable performance. Each socket features clear-size markings and nickel chrome plating for corrosion resistance, all housed in a case with a removable insert.