Product review (5 stars): Best dryer vent
If you live in the north, it is an excellent investment.  My husband and I were looking for a dryer vent that would keep out the cold air and work well to vent the dryer.  Our regular dryer vent would stick open and the laundry room was always freezing. This closure was the perfect solution.  We even spray painted it to blend in to our outdoor dcor.