1,000v Insulated 1/2″ Whitworth Open Ended Spanner. Made from injection moulded Nylon Thermoplastic, which exceeds the requirements of IEC 60900, the industry standard for live line working. In addition, this tool meets the requirements of Category ‘C’, which requires it to perform at extreme temperatures of -40C to +70C, making it unique in this category. These insulated tools are the toughest in the market, being virtually indestructible. With a lifetime warranty on the tool and insulation.