My wife and I bought our present mattress a few years ago after visiting a bed shop that had a mattress with electric motors inside. We lay on the mattress (felt a bit daft), the salesman gave each of us a remote control on a cable, and by pressing buttons we each got the degree of softness/hardness in our sides of the mattress that suited us. Then the salesman noted the numbers that were on the remotes, and we got a mattress that was a bit softer on one side than on the other. Doesn't have any motors in it, though. Very comfortable mattress.