Description: Professional Quality System of Measurement: Metric Type: Deep Impact Sockets Drive Size: 1/2in Heat Treated Hardened And Tempered CHROME-MOLYBDENUM Steel Use On All Air Powered & Battery Powered Impact Tools/Wrenches, Also Breaker Bars/Strong Arms & Torque Wrenches All Sockets Are 1/2" Square Drive & 76mm Deep (From Top To Bottom Of Socket) With 6 Sides (Hex Shape) Each Socket Has A Drilled Head To Locate Retaining Ball Bearing On Most Breaker Bars & Impact Wrenches To Ensure A Safe Secure Fit FOR True IMPACT For Exceptional Strength & Durability Package including: 9 * Deep Impact Socket Set 1/2" Drive Metric Axle Hub Nut Socket .