The Raypak Electric Spa Heater consists of a sheathed low watt density resistance element installed in a copper tank. This tank had a 1-1\2" threaded inlet and outlet on the side for plumbing connection. The heater voltage is only 240 V single phase. The control circuit passes through a manual switch, the temperature control and magnetic contactor coil. All items are pre-wired and installed in a baked enamel steel case. Available in two compact models 5.5 kW and the 11 kW.