The Series P4 PPS Flow Switch features a molded plastic construction for enhanced performance. Monitor liquids with fixed set points from 0.1 to 1.5 GPM. Choose normally open or normally closed SPST or SPDT hermetically sealed reed switch technology. The industrial switch features PPS (polyphenylene sulfide) R4 housing and piston, 316SS spring, fluoroelastomer O-ring and Epoxy. The inlet and outlet ports are 9/16"-18 UNF- 2B thread with optional 1/8" and 1/4" NPT or 1/2" barbed adapters.