1-mile visibility for sail or powerboatsunder 12 meters (39.4')Meets NMMA Certification Procedure. 12V DC - 8 CP lamp included. Predrilled with two countersunk holes to accommodate #8 screws. Housing is chrome plated zinc with black plastic base.Size: 4" x 3-1/8"(10.6cm x 7.94cm), 1-3/4 H (4.4cm) base dimensions.