Product review (5 stars): Awesome replacement for cheap builder aluminum noisy vent hood
Finding this in brown matched perfectly.  Installed it is close to flush with wall of house, very un-noticeable compared to the builder aluminum hood that banged load with a wind.  Great Find!  To replace old one, I peeled-off the aluminum flange from the 6" pipe going to it then cut-off the flange. This just friction-fit inside the 6" pipe tightly using rubber mallet.