Product review (4 stars): Dryer Vent
The dryer vent was good quality, thick plastic and the movable shuttle inside glides easily to lift when the dryer is on and close when it is off.  I've had it installed for a couple of weeks and it has been working fine. Luckily we haven't had much cold weather yet, so I can not say how effective it is at blocking the cold air.  The only complaint I had was that the portion of the unit that mounts to the house was significantly larger than the older vent I was replacing.  I had to trim all four edges with a dremel and re-drill the mounting holes.  Not a big deal, just an added step that made the difference between 5 stars and 4.