Product review (4 stars): Would be better if it had more than 3 locking clips.
I wish it had more than 3 locking clips.  The weight of the duct pulling down on it pulls it away from the wall a tiny bit.  My advice, install it with 1 of the 3 locking clips at 12 o'clock.  I installed it with 1 at 6 o'clock.  Otherwise it seems to work ok, no lint blowing into the room so maybe it's not that bad.