With a larger lamp size and greater visibility, these navigation lights from Hella Marine are optimal for boats up to 657” (20m) in length. Completely waterproof, yet vented casings are made from impact and UV resistant polycarbonate. This break-resistant and wear proof polycarbonate housing snaps together without screws for easy assembly. Bulbs hang to reduce corrosion on the socket. 25W bulbs in colored lenses are visible up to two nautical miles. Rubber grommet insulate wires from sharp edges Polycarbonate case is shatter proof, shock resistant and UV resistant Screws included Two flat plug connectors, 6.3mm United States Coast Guard and internationally approved