Product review (5 stars): Redirect your dryer exhaust
Needed to save the grass in my back yard from getting dried out in the summer when running my dryer.  I switched to this vent instead of the angled flaps. Now the side of my house looks like a steam boat but my flower bed and grass are doing better.

Pros:
Easy to install
Easy to clean the trapped lint out (should not happen that often but in case)
Vents down instead of out and at an angle.
Keeps critters and cold drafts out.

Cons:It's fairly big and sticks out from the house.