Internal tank, coil and stainless steel external cover. The tank has a 5-year guarantee against leakage problems. Operation with 750-watt 220-volt [1:nickel-plated copper resistance, or with heat exchanger connected to the engine cooling system. The resistance is positioned on the lower part of the boiler to avoid heat stratification. Fitted with double safety thermostat, 4-bar safety valve with check valve that reduces or blocks water leakage by expansion. Polyurethane foam insulation, horizontal or vertical installation. Thermostatic mixer 50.189.58 to buy separately.