To use with pumps and heaters without any wiring hassle. Just plug your water (bottom receptacle) and chemical dosing pump (top receptacle). The flow switch has a 10A microswitch that provides closed contact when there is a water flow and open contact when there is no water flow. The microswitch is prewired to remove any wiring need. The flow switch provides dual receptacle in a weatherproof box and in-use cover and 9 power cord with NEMA 5-15 plug. All UL rated components are used in construction. The bottom receptacle is always HOT (powered) and can be used for a water pump. The top receptacle turns ON/OFF with the microswitch and can be used for single phase chemical dosing pump. Micro Switch Rating: 10A Maximum Voltage: 230V Turn On at and above 1.1 GPM flow. Turn off at and below 0.5 GPM flow. 1" PVC Inlet and outlet socket connections, Glue type, insert 1" pipe into the flow switch and glue it. Wetted Surfaces - PVC, Polypropylene, Buna N, SS304 Line Pressure: 90 PSI Temperature: Up to 110 deg F Underwriters Laboratories recognized. 10A micro switch prewired with 9 14/3 AWG outdoor rated cable for high current.