6 Inch Draft Blocker Backdraft Damper Duct Draft Stopper One-Way Airflow Ducting Insert Backflow Preventer Inline Fan Vent Deflector

good valve

I had a high volume of backdraft coming out of my over the range microwave making the kitchen 12 degrees colder than the rest of the house when it gets cold. I played with the baffle that came with the microwave, which involves taking down the microwave each time, bouncing between allowing it to work but really not stopping any backdraft to it getting stuck preventing any stove venting getting through. If I had bought this 17 dollar (6in black) item before this last cold spell I would have saved hundreds of dollars on heating. Everything is quality with this. For such thin (lighter is better) sheet metal the vanes are perfectly flat and square making full contact with the generous gasket keeping all air out of the house. The lowest setting on the vent fully opens the vanes. Even the paint job, where only a 1/4" section can be seen when installed, looks high quality. Easy to install just pop off the vent cap outside, drop this in to the vent pipe (I then duct taped it because I didn't by a clamp) then tighten the vent cap back on to the other half of this.

Everything was fine

Was hoping it would be sensitive enough to use on my air exchanger at low speed and it is. Exactly what I needed.

I installed this inline for my over the range microwave oven. The damper that comes with the microwave oven wouldn’t work properly with a rectangular to round adapter. I tested this before final install and it worked fine. Just be sure you have the flow direction correct. I did find it difficult to get the aluminum vent pipe to mate with the damper. I finally got it then taped it real good.

This damper worked perfectly to solved my problem. It is quiet and installation was simple

Fits nicely inside a 6 inch pipe. I used it in the pipe from my cooktop downdraft to the remote blower. The springs are not strong enough to hold the flaps closed when mounted vertically. Don't know if a back draft will close them. I wanted it to keep the cold air outside.

Just what i needed. Fit and worked great.