The Dungs AA...C2/A2-7 differential pressure switches are field adjustable, compact pressure switches for automatic burner controls. AA...C2/A2-7 differential pressure switches are suitable for making/breaking a circuit when the medium pressure changes relative to the set point. Not suitable for natural gas, propane, butane, and other combustible gases. Can be used as a pressure, vacuum or differential pressure switch for air and non-aggressive gases.