To use with pumps and heaters. The flow switch has a 25A microswitch that provides closed dry contact when there is a water flow and open contact when there is no water flow. Wiring is required by licensed electrician. If you prefer prewired, please check prewired option listed on our website. Base Part Number: 57-F1-2215-00W Micro Switch Rating: 25A Maximum 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 in to the flow switch and glue it. 1-1/4" PVC Inlet and outlet spigot connections, Glue type, Insert the switch in to 1-1/4" sockets and glue it. Wetted Surfaces - PVC, Polypropylene, Buna N, SS304 Line Pressure: 50 PSI Temperature: Up to 110 deg F Underwriters Laboratories recognized. 10A dry contact. 1/2" Electrical Conduit Connection