Specifications: Auto control: Default On(Cut-in) pressure: 90PSI, Default Off(Cut-out) pressure: 120PSI Adjustable Air Pressure Switch: Min On(Cut-in) pressure: 45PSI, MAX Off(Cut-out) pressure: 140PSI, DIFFERENTIAL: 30-40PSI Heavy Duty Air Pressure Switch: AMP RATING:26A at 110/240VAC, Maximum Working Voltage: 240VAC,4 Female 1/4" NPT Ports, w/ a ON/OFF switch Lever & Unloader Regulator Adjust Pressure Range : 45 - 140 PSI (Cannot boost pressure) Regulator Adjust Pressure Range : 45 - 140 PSI (Cannot boost pressure) The working pressure of the safety relief valve is 120PSI. If you adjust the pressure switch over 120PSI, you need replace it with new one.