This hook-up wire construction is capable of resisting high temperatures of up to 125°C (257°F); the XLPE coating also protects the wire from abrasion, oils, chemicals, fuels, and solvents, while also remaining flexible enough to fit wherever it might be needed. This 18 gauge GXL Automotive Primary Wire is a durable type of hook-up wire consisting of stranded copper conductors and a thin-walled, cross-linked polyethylene (XLPE) insulation.045" Diameter, 60 Volts. We also offer 7 different spool sizes for your convenience.