After a couple of hot camping trips we decided we wanted ceiling A.C. vents to not only be directional but also with louvers to close them down (in certain areas).
Finally found a place that had an exact replacement. Bought five of them and took about 25 minutes to replace them all.
Found them from D W Inc. in Elkhart, Indiana for $4.00 each. Part number is "Spaceport 8840 vent". And if you want to trim it up ( conceal screw heads) then order the "Trim Ring" for $1.50 each.
Their website is
http://www.dwincorp.com/categories/1/AC-Vents
Now I can block off some of the cold air to the bathroom. Boy that toilet seat would get COLD!!!
Happy trails,