These 120V stainless steel water heaters are corrosion resistant and feature aluminum tanks with stainless steel casings. A 7/8'' heat exchanger ensures more efficient heat control through increased surface area. Complete ignition protected controls, high temperature, and high-pressure valve installed. For maximum safety the temperature control valve controls coolant flow through the heat exchanger. The control valve prevents excessively high water temperatures and reduces the risk of scalding. It maintains the potable water output temperature at a safe level of approximately 140 degrees. No maintenance or electrical hookup is required. These units are available in 6, 11, or 20 gallon sizes.