Porcelain-lined, steel water heaters feature an anode rod to "absorb" the electrolytic action, ensuring that your water heater lasts longer. With the fastest recovery in the industry of 10.2 gallons, six and ten gallon water heaters give you more hot water. Copolymer insulation jackets specially fit the tank to retain heat. For higher recovery, use the gas and optional electric element water heaters which use a 1,440 watt element to recover an additional 6 gallons per hour. RV water heaters with re-ignitor eliminate the need to relight the pilot. Easy to install, operate and maintain. Three gallon features 9,000 BTUs and is 12-11/16"H x 12-11/16"W x 16-1/8"D. Cutout size: 12-3/4"H x 12-3/4"W.