I was skeptical, but I bought a dual foam 3 inch from (don't hate me) Walmart. it was $99.00. We have a RP-172 and use the dinette for a short queen. We fold the table down, arrange the cushions. I made a 1/4 inch luan stiffener and used duct tape for the joints, I can fold it up and roll up the mattress with bungee cords when not in use. Donna and I have a little dance that takes about 3 to 5 minutes. table down, cushions arranged, stiffener folded out, put foam mattress down, unhook bungee's and leave then on the bottom, roll out mattress. At this point I leave while she makes the bed up. This dog gone set up sleeps almost as well as our sleep number bed at home. it is very comfortable and very supportive of our old backs. Then we pop a Andy Griffith DVD in and in about 30 minutes it is lights out. After a good day of poddin, hiking, fishing, cooking out on the fire and enjoying the twilight, we sleep like two bugs in a rug