This mattress contains 1000 pocket springs, these are individual springs that move independently from each other. As they move separately it means they only support you where you lay and will eliminate the 'roll together' effect. The roll together effect happens when two people of uneven weight unintentionally 'roll together'. The Backcare Extreme also contains sumptuous layers of white fibres, all hand tufted in a lovely damask with two rows of side stitching.