Unique Bargains - 5 Inch HVAC Duct Manual Volume Backdraft Damper, Adjustable Airflow Ducting Branch Vent Damper with Silicone Seal - Silver

The manual volume damper is used for air volume regulation in an air ventilation system, and it is widely used in the HVAC industry. With that installed in your HVAC systems, you can easily control the airflow rate or close off an air duct if needed, to some extent, it will increase the energy efficiency of your system.