Beautyforall Heavy Duty Air Compressor Pressure Switch Control Valve 90-120PSI Air compressor pressure switch is an extremely imperative element as it is used to switch on the energy and to switch off the motor of the compressor. Widely used for pool and spa, anti-skid braking systems, water pump systems, and dental air compressors etc. It features different diaphragms for compatibility with a wide variety of fluids, and various terminations including a Metri-Pack connector that forms a tight seal when connected. There is a red ON/OFF switch knob. Best Replacement for your old or broken one!