The Cleveland Controls AFS-145-112 SPDT Air Pressure Switch is a pressure-sensing control designed to monitor airflow and pressure conditions within HVAC systems, with an operating range of 0.05-12 inches water column. It responds to pressure changes by switching electrical contacts, helping control or verify proper airflow. This switch is commonly used in furnaces, air handlers, vent... https://www.partshnc.com/cleveland-controls-afs-145-112-spdt-air-pressure-switch-0-05-12-wc