Porcelain lined steel tank. Industry exclusive flue tube baffles - slows combustion process to transfer more heat to water in tank. Repositionable module board provides installation flexibility Backed by a 2 year limited warranty and the tank is backed by a 3 year tank limited warranty Assembled in the USA Unit Dimensions: 12.50" h X 16.125" w X 17.625" d Cutout Dimensions: 12.625" h X 16.25" w D Model gas ignition can be controlled from the convenience of your RV Water heater door sold separately.