2 nautical mile visibility. Meets ABYC, NMMA, R.I.N.A. requirements. Approved for Boats to 66'. Constructed of UV resistant fiberglass reinforced ABS plastic with UV resistant plexiglass lens. Lights are completely gasketed and seawater proof. Tube made of aluminum. Complete with 12V-10W bulb. Mounts with 2 #6 STS PH screws.