Product review (5 stars): Excellent product
We live in the country, and have lots of little critters about--bugs, mice, blacksnakes; etc, and needed a vent cover that seals securely when not in use.  The Heartland Vent Closure does that.  It was easy to install on our vinyl siding.  If I were going to complain, it would be that the device was not painted when we got it, so we had to do that (to protect it from u.v.).  It would have been simpler, and worth a couple more bucks to me, if the manufacturer had just sprayed a coat of white on it at the factory.
We will be building a new house this fall, and I plan to buy another of these devices for the new house.