The Rheem-Ruud 42-105601-33 Pressure Switch is a safety control designed to monitor pressure conditions within HVAC equipment and help ensure proper system operation. It responds to changes in air or vent pressure and signals the control system when the required pressure is achieved, helping regulate safe operation. This pressure switch is commonly used in Rheem-Ruud furnaces and heat... https://www.partshnc.com/rheem-ruud-42-105601-33-pressure-switch