Product review (4 stars): Buy it for parts
For those of you who are looking to replace an original Deflecto Supurr-vent - the size of the backing hole on this is slightly larger (since it's not inset in from the 4" hole). Since that meant it wouldn't fit in the hole, and I didn't want to carve a new hole, I just cannibalized this to get the flaps and put it onto the old supurr-vent we have, fixing the problem (for now).

So - 4* because if fixes my problem, but it'd be best if it were *actually* the same size as the original.