3-mile visibility for sail or powerboats under 66'. Anodized aluminum 3/4" tube with clear lenses. Two 12V DC 8 CP lamps included. Chrome plated zinc base is 2-7/32" L x 5/8" W. Pre-drilled to accommodate 2 #8 screws. 10-1/4" overall length. Two plastic adapters included for flat or "V" mount.