USCG Certified for use on power driven vessels under 20 meters (65.6 ft.) in length. 2-mile visibility. Black plastic top with clear fluted lens and frosted globe, black plastic base, and 3/4" diameter anodized aluminum tube. Plastic adapters for flat or "V" type mount, contains notch for through-base wiring. 12V bulbs included. Screw size is 8. Housing Black Mount Horizontal Height 13-3/8" Base 2" x 1-1/2"