The Dungs Pressure Switches 266943 12–60 Inch W.C. M/R Gas Pressure Switch is a gas pressure monitoring device designed for compatible commercial boilers, furnaces, and industrial burner systems. It detects changes in gas pressure and activates an electrical contact when pressure reaches its preset operating limits. This helps monitor gas supply conditions and supports safe burner ope... https://www.partshnc.com/266911-dungs-pressure-switches-4-4-inch-wc-532-inch-air-switch