Product review (4 stars): A Good 4 Stars , but 3 items for me
Works well with Deflect-O 4in Back Draft Damper (BD04) makes a nice tight fit to Deflect Ultra Seal. However I wish the inside had a screened vent  not big holes as our dryer goes right into the carport, and the previous deflecto Dryer louver 4 Inch one we had dry rotted (wanted to replace any way do to the lint escape). so three items for me that do not make this a 5.

1). There should be a metal screen inside to capture the lint.

2), as noted in other reviews an additional adapter is need such as the BD04 (if this works for you I highly suggest do to the snug fit as this has ) or other 4 in tube (these tend not to have such a snug fit and if the size is off just by a bit the aluminum buckles.

3). not sure why the top bracket/screw holes are further out, I was able to adapt my and pull in, but if you search on the internet, you will see some pictures of this item mounted and the top bracket is away from the wall by about 3/4 of an inch with no screws attached.