Laybrooks adjustable bed pocket memory sprung mattress are specifically designed for all types of adjustable beds. The spring count depends on the size of the mattress 3ft, 4ft, 4ft 6 5ft or 6ft. As an example a 5ft mattress has over a 1000 springs. We use a very high grade visco elastic (memory foam) & all mattresses are made for the individual customers weight & how they like the feel, soft, medium or firm. We use different densitys of foams to give the different firmnesses & they have a firm edge support so the mattress does not collapse when sat on the side.