Product review (5 stars): Great Dryer Vent Cover
This is a great vent cover, especially if your dryer vent is surrounded with foliage and might eventually interfere with the functionality of the louvered type.  In this one, the moving parts are all on the inside.  One takes the cover off only to clean out the dryer duct (which should be performed annually, NO MATTER HOW CLEAN YOU KEEP YOUR DRYER LINT FILTER).

It says that you can paint the closure.  I used brown primer (I have a brick house) since plastic tends to photo oxidize).  So far, it is working well.