This Pressure Switch is adjustable for spa heaters! It has a 1/8" NPT thread, with non-latching, momentary, snap action. This switch is approximately 2.6" tall so it will need about a 2.75" clearance diameter for installation. This universal hot tub switch can replace parts by Barksdale, Len Gordon, Herga. It can also replace older Tr-Delta pressure switches (series 3029, 3029P, 4000). - Plastic 1/8" Male Pipe Thread SPNO - Pressure Switch - 1-5 PSI - 25A
