We had the sleep by the number beds twin long beds to replace our queen sized beds that was adjustable for back and legs and vibrated also. We had a Doctor sign that we needed it and got a big discount. Down side of that was we moved to retire and they were very heavy to move. But enjoyed every night on them for good many years. Replaced the mattress on one, and its in the guest room still going. Very firm, but not like a table or floor.