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

Stops outside air from coming into the dryer. Easy to install, ensure you get the airflow direction correct.

Wasnt avail at big box stores near me so I scrambled to order this for my contractor installing the ductwork for my new kitchen stove vent. He said it was perfect and easy to install. It seems to be working great and our city inspector specifically went out of his way to check it. Passed without issue. Recommended.

Works well and open completely with a over the range microwave hood.

Excellent quality, good price, and easy installation.

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.

Works great. Easy to install. Even easier to order since this size of damper seems harder to find at the big box stores.

Fit and function is good Appears to be durable

These don't seem stiff when I push them, but I had to step up to a stronger fan to open them. Even then, they flutter and make a lot of noise.

it works very well...no more cold air in my kitchen.

Exactly what I ordered and delivered the next day. Installed it and works perfectly.

Good price, seem decent quality, springs haven't jammed yet

Excellent design, construction, and workmanship. The shell is made of rigid sheet metal and the butterfly dampers of aluminum. The dampers are normally held in the closed position against the seal by light springs. The dampers open in one direction by just blowing against it. Both ends of the shell fit perfectly inside 4 inch diameter ducting. The plain ends allow it to be easily installed in an existing ducting that needs a backflow preventer. It even had a sticker noting how to orient the dampers properly when installing it horizontally. I used it to prevent wet exhaust from our clothes drier backflowing to our washroom. Both drier exhaust and washroom vent were tied to a tee that exhaust to the outside. Our washroom vent fan damper was not enough to keep moist air from our drier from backflowing into our washroom.

Awesome little Backdraft pipe 4-in adapter even has a little bit of air support so it doesn't push through the cracks with the liner inside the pipe