Spa and Hot Tub Heater, Min. Flow Rate 15 gpm, Inlet Size/Bushing Size 1-1/4 in NPT, Unit-Mounted Thermostat Included, Voltage 240V AC, 1 Phase, Wattage Output 6kW, Amperage 25A, Control Type Mechanical Selector Dial, Overall Length 19 in Immersed, Overall Width 22 -1/2 in, Heating Method Immersion, For Use With N15/03099/N15/03101, Standards UL Recognized