11 gallon capacity, 110 volts. Corrosion-resistant heater with aluminum housing and stainless steel casing. A 7/8" heat exchanger with 1/2" NPT thread ensures easy installation. Heat control is more efficient through increased surface area. Comes complete with ignition-protected controls, high temperature, and high pressure valve installed. Measures 16" wide (mounting feet not included, w/feet is 18") x 22" depth x 16" height.