Ancor Tinned Copper Wire Single 18 Guage Black (By/Foot). Manufactured from tin coated copper strands for maximum protection against corrosion and electrolysis. Resists fatigue due to vibration and flexing. Premium vinyl insulation is rated at 600 volts, 105 deg C dry and 75 deg C wet, stays flexible even in extreme cold (-40 deg F/C) and resists salt water, battery acid, oil, gasoline, heat, abrasion, and ultra-violet radiation. Exceeds all UL1426, US Coast Guard Charter boat (CFR title 46) and ABYC standards.