Product review (2 stars): Cheaply made and the valve leaks moist air when it is set to vent outside
I purchased this at Menards and promptly returned.
Basically, it is very cheap. The two pieces that make up the housing don't form a hermetic seal (not that you can't just use some foil tape or duct seal). I installed this rather quickly and sealed things up well.

On my test run, I noticed that warm, moist air was blowing right through the vent. Granted, much of the air was deflected outside, so it is better than just dumping all the air into your house.

Also, I felt that the lint screen was inadequate. The mesh isn't fine enough to catch the small pieces of lint that make it into the vent. The screen really might as well not even be there.

So, I'm back to doing what I did before: remove the duct from the outside vent, point it inward during the winter, and plug up the exterior vent with some insulation.