Product review (5 stars): Everyone should have this!
I installed this on our 100 year old farm house this summer when we installed new siding. Seemed like a good time to do it. In previous winters it seemed like the wind blew straight into our dryer. It would get so bad I would sometimes have to place a rag inside the outer vent to cut down on the draft. Not this year. No more draft, the dryer is only moderately cool. The unit mounts securely to the outer wall and seals up any of the space which is usually open around the vent. I believe it will pay for itself in energy savings in the first year.