6 Inch Backdraft Damper Back Draft Vent Duct Shutter Blocker, Backflow Ducting Insert One-Way Airflow Preventer with Inline Springs Loaded Folding Blades, HVAC Extractor Range Fan Hood Deflector

This is a good quality, well built dampener. It uses a high density foam weatherstrip on the back for the wings to rest against. This helps seal it up nicely when not in use. This is FAR better than the typical Chinese junk you see. Very happy and will recommend to all.

Works great. Nice seal and very quiet

I really like the seal inside that the dampers seat against when closed. Fits perfectly in the 4" exhaust duct. Using it to seal out outside air from entering the indoor greenhouse through the exhaust fan duct.

esta muy bueno y util el producto

Arrived within a few days. Good quality. I used it to prevent backdraft in a dryer vent. The air from the adjacent bathroom fan no longer goes into the dryer.

I opened up my recent installation and this does not work and constantly opens up with every small breeze from the exterior. What is the point if it lets air into the house and so slow to close because of weak springs. Total waste of time and money.

Good price fast shipping excellent seller

Very sturdy and higher quality than most