Square D FSG2J21M4CP 30/50 PSI Standard Pressure Switch with Low Pressure Cutoff
The Square D Pumptrol™ by Schneider Electric Water Pressure Switches have been providing rugged, reliable performance for over 67 years.  These switches are designed to control electrically driven water pumps and air compressors.  They can be used for jet pumps, submersible pumps and reciprocating pump applications.