Product review (4 stars): Great vent for the price I pad for it!
This thing is a beast!  Works great as ventilation system for basement brewery.  Had some condensation build up around the removable grates during the boil but was able to wipe it down.  Only giving 4 stars because the vent was 8" (as opposed to what 6" as I was led to believe), and some of the parts were banged up in shipping.  I had to use a couple sheet metal screws to keep the frame together, but they are out of the way and not noticeable.