Sea Dog Combination Bow Light 400155-1 Note: Not for new construction, for replacement of existing lighting. All USCG approved navigation lights must be mounted properly to provide the correct visual alignment and allow unimpeded sight lines. Please refer to United States Coast Guard regulations for 1 NM and 2 NM navigation lights for more information. Features: Dimensions: 2-7/8" X 2-9/16" X 1-1/2" Fastener: #10 FH