12-AWG Copper THHN cable has 0.004-Inch purple nylon jacket to withstand harsh environmental conditions. The 0.15-Inch PVC insulation resists electrical leakage and offers protection against environmental threats. It has outside diameter of 0.121-Inch. It has current rating of 20-Amps and voltage rating of 600-Volts. It withstands temperature rating of 90 deg C. This 2500-ft cable comes in a reel. Cable meets NFPA 70 2008 standards.