The International Comfort Products 1174276 SPST Pressure Switch 0.59" WC is an OEM safety control designed for compatible gas furnaces and other HVAC heating systems. It works by monitoring the system's air pressure and verifying proper inducer blower operation before allowing the ignition sequence to continue. If the required pressure is not detected, the switch interrupts the heatin... https://www.partshnc.com/59wc-spst-pressure-switch-2