The stock AC diffusers in our coach were not adjustable, forcing the cool air in a single direction, usually down the center of the coach. On hot days it would be nice to have some of that coolness blowing directly on you when sitting on the couch or recliner.
I found these on Amazon and installed one that seems to work super, directing air to the couch and recliner. They fit the existing opening with a bit of sanding and use the existing mounting holes. A coat of primer and 2 coats of shiny brass and you're done.
Steve
http://www.amazon.com/ADJUSTABLE-DIFFUSER-Register-Sidewall-Cieling/dp/B006J2VDHW/ref=cm_cr_pr_product_top?ie=UTF8