PRO-GRADE&Trade; 1/4" DRIVE SAE & METRIC SOCKET SETS Professional-quality Pro-Grade™ SAE & Metric Socket Sets are designed to perform and built to last at a great price! Heat-treated chrome-vanadium steel construction meet or exceed ANSI specifications. Feature exclusive Dyna-Drive™ Torque System on working side, 4-sided ball detents and chamfered and recessed leading edges. Includes clip rail or convenient carrying case.