For smaller high-voltage applications like heater cores, air conditioning motors, controller precharge wiring and that insane 2kW blue underbody lighting array you're building, we offer a 600V rated primary wire in sizes 8 through 14. Unless you know what you're doing, don't use regular parts store automotive wire for this! Most of that wire is intended for regular 12-14V accessory systems, and typically has an insulation rating of only 50V. Do it right - use the right stuff. NOTE: If you're going to use that 300V pack to power your hood-mounted railgun through this stuff, we do ask that you send us pictures.