Product Description Insulated Metric Socket 3/8" Drive. 15.0 mm. Socket chrome-vanadium steel, forged, oil-hardened. 1000Volt rated. From the Manufacturer Wiha 31515 Insulated 3/8" Drive Metric Sockets, 15mm. Insulation according to VDE, EN/IEC 60900, DIN 7448 specification, up to 1000 volt. Individually tested, chrome-vanadium steel, forged, oil hardened.