Product review (1 stars): Do NOT waste your money!!
Despite the non glowing reviews I read, I bought 2 of these anyway.  Shoddy construction for sure!  Several of the reviews mentioned that the screen does not contain the lint so after busting out the scissors and a pair of tights I realized that they were all I needed.  I attached the cut off tight to the end of my vent with a rubber band and promptly packed up the UN-needed heat keeper.  When June hits, I will reattach the vent to the outside wall.