Review on Klimapartner RKI Backdraft Damper Inline by Ryan Pollock

Jokes aside, this was exactly what I was looking for but could NOT find at my local hardware store. It fits snugly in a standard 4 inch duct and prevents outside air from flowing back into the house through the dryer. The first winter when we bought our house, it was always cold in the dryer. So I had to replace the outside hood, but I took it a step further by adding a check valve inside the house to create a small pocket of insulating air. Check out the photos I have attached of the installed item in the closed and open positions and a video of it in action. Hooray!