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

I decided to use the dryer vent to run my portable ac exhaust and it was backing into the dryer. This was easy to install and it worked perfectly and now I can keep my room cool without having to block my already tiny window that’s a hopper style

Great product. Easy install works great

Strong. It opens easily with very slight pressure. Closes quickly and seals up great. It actually slides inside the pipe snugly, which is great, because your pipe length does not change. Very impressed. It is also whisper quiet when it opens or closes.

Perfect for what I needed; my bathroom exhaust fans, although they have their own dampers, leak outside air into the house as if the vent was wide open. This was causing some major condensation issues so I decided to try these dampers. So far, I have noticed a huge difference with absolutely no outside air leaking into the fans. The quality is pretty good for the purpose it serves; however, one of the springs on one damper was much looser than the other damper so I did shave a star off for obvious lack of quality control. Overall, this seems to work really well for me and I would recommend these dampers for those in the same situation as me.

I bought this to help seal the outside.I kept having a draft come in and making the kitchen cold. Size is perfect!Airflow is controlled.Great value since I can keep electric down.

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.

If this vent is installed with the air flow going down, the springs will be challenged to close the vent due to the weight of the fins. Likewise if the orientation is horizontal with the hinge flap horizontal, the spring will struggle. The construction and fit is solid with a good seal when closed. Will do the job keeping in mind these conditions.

Performed for me as expected.