The ITL Insulated General Purpose Open End Spanners are made from injection moulded nylon 11 which exceeds the requirements of IEC 60900, the industry standard for live line working. Only the handle is insulated to allow access into tight spaces. In addition, this tool meets the requirements of Category 'C', which requires it to perform at extreme temperatures of -40°C to +70°C, making it unique in this category. These insulated tools are the toughest in the market, being virtually indestructible. With a lifetime warranty on both the tool and insulation, plus a 30 day no quibble money back guarantee.