Product review (5 stars): So simple, yet so effective.
Living in Maine has some advantages; Four distinct seasons, woods to walk/ski right off the porch, and no poisonous animals.  One of the challenges though is the CCCCOOOOLLLDDDDD.  Since buying our first home we've had the challenge of keeping our first floor bathroom warm with the washer and dryer being located there.  We had tried different vents until we found this one listed.  I bought one and installed it the day after it arrived, on one of the coldest days this year.  The results were immediate.  Our bathroom is MUCH warmer, in fact.. it can no longer be considered cold and we no longer fear getting out of the shower.

The only draw back is that my wife does a LOT of laundry and she and my daughter have a LOT of colored clothes.  This air flow results in the link blown out to collect on the side of the house instead of  blowing away from the house. But after a couple weeks a quick wipe with a damp cloth takes care of that.

A+! BUY!