Pocket springs are manufactured from individual high tensile steel springs, wrapped in their own pocket of fabric. A fabric pocket is used to cover each spring so unlike other spring systems this allows them to slide up and down independently. Every time you get up from a pocket sprung sofa the springs expand, maintaining the shape of the seat cushion. A sofa using pocket springs will last longer than a sofa using a lower quality block foam interior. Block foam can break down with time and lose support. With a pocket spring system, you will receive consistent support throughout the life of the sofa.