Dayton 3hhl4 Backdraft Damper Vert/horiz Mtg

This model is a non-flanged exhaust backdraft damper. The blades 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.