Product Details: The Airsource Low-Pressure Switch is designed to monitor the system pressure and shut off the compressor when the pressure drops below a certain level. This switch is designed to fit M12 thread size and is a normally open switch with a pressure range of 22-32psi and 3-9 psi. It is designed to work with R134a refrigerant type and is essential for any air conditioning system. This switch helps to prevent the system from running with inadequate pressure, which can cause damage to the compressor and other components. It is easy to install and is a reliable and durable switch that will provide reliable service. FleetPride is your First Click in Heavy Duty®.