Yes, mine has the rear twin beds with curve. I used a sheet of plastic and made a template by laying it on the bed support. That way they were able to size it perfectly. There are two versions, one with a heavy nylon cover and one with a typical mattress type cover. I chose the nylon cover. It has an inch heavy dense foam, 3" of medium foam and 1" of memory foam on top. They also have a zipper on the back curved side. She did mention that you could get 2" of memory foam for a 6" thick mattress.