Product review (4 stars): Great vent, works as advertised.
After 10+ years of having a cold bathroom I decided to look for solutions. I settled on the Heartland 2100 Dryer Vent Closure. I bought it at my local Menards store for $14.99 + tax. Once I got it home I wanted to install it and found that the screws were missing. It didn't matter because the screws I was going to need were much longer. The construction itself is well done although I'd like to see the flange be a little thicker. Installing it on vinyl siding meant that the screws "pulled it in" a touch. The design of the vent itself is better than I expected and here's why: I thought that the "float cap" was the cap one sees on the top of the picture. This worried me because I live in a place where it snows and I worried about snow piling on top thus keeping the cap from "floating".

The float cap is actually inside and what you see on the picture is the stationary cap that actually keeps the "floating cap" inside while guiding the flow of the air downward. So, the air blows out, pushes the float cap up, hits the visible top cap and gets pushed down escaping out the bottom of the fixture. Since I just installed it I wil keep an eye on how it performs over time. Two other issues I ran into: I had to force the existing pipe into the vent as it didn't fit inside the vent initially. The other thing was that the opening in the wall was bigger than the pipe allowing cold air (and maybe mice!!) to creep in thru it. I used expanding foam around the pipe to fill the hole.