The Siemens 331-2961 Pneumatic Damper Actuator is a precision control device designed to regulate airflow in HVAC systems. Operating within an 8–13 PSI range, it converts pneumatic pressure into mechanical motion to pivot and position dampers accurately. Commonly used in Siemens air handlers, ventilation systems, and duct control assemblies, it helps maintain proper airflow balance an... https://www.partshnc.com/4-pivot-act8-13ext-temp-rg