Square D by Schneider Electric FSG2J24M4CP 40-60 PSI Pumptrol Water Pressure Switch with Low Pressure Cut-Off Square water pump pressure switch for control of electrically driven water pumps Diaphragm actuated Includes 2 1/4-inch poles 18 NPSF internal thread with 1/4 opening 220 PSI maximum pressure rating with low pressure cut-off at 40 PSI