Black 14 gauge appliance wire is the equivalent of type 90C thermoplastic. Designed specifically for furnace wiring and other high-heat applications. 14 awg, stranded, THHN or THWN, 600V, 90C, T90 Nylon or TWN 75 FT1. Nominal pvc insulation .016", nominal nylon thickness .005". Price is per foot. Adjust quantity for longer lengths.