Campbell Hausfeld CW211401AV Air Compressor No Unloader Valve Pressure Switch 120/150 PSI provides automatic pressure control for compatible air compressors. This replacement pressure switch monitors tank pressure and controls the motor between 120 and 150 PSI. It works by turning the motor on as pressure drops and off when the preset maximum pressure is reached. The no-unloader desig... https://www.wholetoolbox.com/campbell-hausfeld-cw211401av-air-compressor-no-unloader-valve-pressure-switch-120-150-psi/CW211401AV.html