I bought this for my Mother. She has really bad knees and her back always hurt. She said that the first night her back never bothered her. By the 5th night her knees are feeling better. I had bought the 10 for my Sister. At first she was thinking that since it came in a box the Bed was going to be Horrible. Well,the very next morning she called me and Thanked Me over and over. Said it was the Best. I Promise that you will not be disappointed and the prices are so Reasonable.