LED Combination Tri-Color / Anchor Navigation Light. Certified USCG, ABYC-A16, 72 COLREGS. 2 Nautical Mile (2NM) visibility for sailing vessels up to 20 meters (65 feet). Rugged & waterproof. 360 mounting bracket (BRKT360) included. The Tri-Color light has a clear window on top of the light that allows the stern light to shine up-ward to illuminate the wind vane for night sailing. Uses five times less power than comparable incandescent Tri-Color lights. The light provides constant brightness over the full operation range of 10 to 30 volts. This insures the light will meet or exceed the visibility requirements as the battery voltage drops from use during night time sailing. This item can be order with and without a photo-cell for auto day / night operation.