This Pumptrol FSG2J21M4CP electromechanical pressure switch is the most trusted brand in residential, commercial and industrial pumping applications. For over 75 years, Square D pressure switches continue to meet the needs of our customers. This switch has a 30 PSI to 50 PSI pressure setting range activates an electrically driven water pump within a power circuit when the adjustable rising and falling thresholds are reached. The NEMA 1 enclosure has a 1/4 inch NPSF internal fluid connection and screw clamp terminals. The switch works with a 1.5 HP or less pump. The adjustable differential range is 15 psi to 30 psi and the cut-out range is 20 PSI to 65 PSI. The low-pressure cut-off (auto-start-off) operates at approximately 10 psig below the cut-in and will turn off the pump. The enclosure is National Electrical Manufacturers Association (NEMA) Type 1 and Ingress Protection (IP) 20 rated. The switch is Underwriters Laboratory (UL) Listed and Canadian Standards Association (CSA) Certified.