High -quality material: Manual volume damper is made of high -quality galvanized iron. It is resistant to high temperature, is not easy to deform, and resistance to corrosion. [Dimension details] The outer diameter of the port is about 10 cm and a height of about 15.5 cm. Simple installation: Just slide the volume damper into the connected pipe and tighten it with a pipe clip and tape. [Used for air balance] The side design has a rotating handle, which can adjust the air volume or close.The balanced damper is not completely sealed and used for air balance, not air termination. Widely used: Our balanced damper can be used for heating air -conditioning systems, air conditioners, and range hoods. You can freely control the airflow or turn off the air duct when needed. Material: Aluminum alloy colour: silver Package Contents: 1set x hvac ducts Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.