Primary Wire GPT Wire Techspan GPT (General Purpose Thermoplastic) primary single conductor wire is manufactured using 100% pure copper conductors with a PVC compound that resists chemical, abrasion and heat, up to 85°C (185°F) . Jacket surface is smooth enough for easy, clean wire stripping . Ideal for automotive, truck, trailers, tractor, boats, and other point-to-point, low voltage applications (up to 60 Volts) . Type GPT to SAE specification J1128 meets the standard for OEM or replacement applications for general purpose requirements .