The GW A2 and GWA4/2 are adjustable pressure switches, which are suitable for activating, deactivating, or switching a circuit if the actual valve of the pressure changes. The pressure switches are suitable for natural gas, propane, butane, air, and inert gases. They are suitable for making or breaking a circuit relative to changes in medium pressure relative to the set point. This specific gas pressure switch has a 2.5 to 50 mbar.