I was redoing the bathroom, replaced the bathroom fans, and noticed the the vents were just laid out to the soffit area. After 19 years, there was no evidence of moisture issues, but knew it could be better. Ordered this bathroom vent. The retro installation went well. It was fairly easy. For a new construction, this would be awesome, but even as a remodel, it went easily. I actually ordered another for the down stairs bathroom. The flapper seems to be very substantial and does a good job of keeping drafts down.
This vent is designed for new construction but I was able to make it work on my old house. I like that it has a built in 90 degree bend so the vent hose doesn't get bent over and restricted.