Product review (5 stars): Great Product
My dryer vent was jammed open letting precious heat out and small critters in.  The man at the local Lowes store showed me cheap replacement vents similar to what I had, but he told me his wife had bought a more efficient but more expensive device online. I found the product and ordered it.  It arrived shortly and I installed it myself.  It was easy and I am all thumbs.  It works just great.  However it is larger than the one I removed, so that could be a problem if you are working with limited space.