Lochinvar & A.O. Smith 100294585 -.68 Inch Pressure Switch is a safety and control component designed to monitor air or vent pressure within compatible heating equipment. It works by detecting pressure changes and activating or interrupting electrical circuits when specific pressure conditions are met, helping ensure safe system operation. Designed for use with compatible boilers, wat... https://www.partshnc.com/68-pressure-switch-3