Built to meet Code of Federal Regulations sub part 161. 010; this rugged water light produces brilliant strobe flashes automatically when thrown overboard and is visible for miles at sea. When used with a 6 volt alkaline lantern battery (not included) it will flash at the U. S. C. G. required rate for over 52 hours and will still flash at least every 2 seconds after 7 days of continuous operation (meets U. S. C. G. requirements - 46 CFR-161-010). A stainless steel molding bracket is included. Dimensions are 11-1/2 long, and 4 maximum diameter.