With its combination of a posturetech 620 response spring system and a comfort enhancing layer of memory foam the sealy pearl memory posturpedic mattress provides comfort and support in abundance the 620 spring system is structured so as to cover the mattress from edge to edge which means a consistent sleeping surface regardless of your preferred sleeping position this consistency helps to reduce the need to toss and turn during the night making for a tranquil and restful sleepthe addition