USCG Certified for use on sail or power driven vessels under 20 meters (65.6 ft.) in length. 2-mile visibility. White translucent globe and black plastic top, black plastic base, and 3/4" diameter anodized aluminum tube. Fixed mount. 12V bulb included. Screw size is 8. Housing Black Height 7-1/8" Base 1" x 2-5/8"