Seaward is a major manufacturer of marine water heaters. Features: Aluminum tank and hold down brackets, dual wall heat exchangers, and ignition protection. UL approved. Model S600 is a 6-gals. water heater with rear heat exchanger. Galvanized steel exterior. Size: 13W x 19D x 13H. 120V/15 amps. Domestic water ports : 1/2’’ IPT. Exchanger ports : 5/8’’ hose barbs. 1 year limited warranty.