Dayton 6WRK7 Backdraft Damper,Horizontal,42 Sq

This model comes with blades which have a felt seal on the leading edge for quiet closing and better protection from the weather. Spring assisted to allow blades to open quickly. Ideal for use in roof curbs, duct work, or wall collars when using a fan or power roof ventilator. Recommended for horizontal mount exhaust applications but it is also available for vertical mount.