14 gauge Black Automotive Wire on a 1,000 foot master spool. Wire is American made from pure copper and the core is made from 19 strands of 27 gauge wire. Black PVC insulation resists grease, oil, and acids, and is temperature rated to 176°F (80°C). Voltage rated up to 60 volts. Meets SAE J1128 and is RoHS compliant.