This is a BRAND NEW Heil/Tempstar/Inner City Products (ICP)/Comfort Maker Gas Furnace Air Pressure Switch. The Part # is 1445-589 and 1445589 (Honeywell/Tridelta Model # is FS6318-513). Switch has 3 wiring terminals and 2 hose ports. It works on many Heil/Tempstar/ICP/Comfort Maker gas furnaces. Thanks for looking and good luck!
An air switch is safety designed to ensure that your inducer motor is running at the proper RPM, and creating the proper vacuum for your furnace to flue safely.