Revolution and Microlution spring-within-a-spring system work together to provide support as you sleep. The double side-stitching ensures that the whole sleeping surface is comfortable to sleep on, right up to the edges. This also offers enhanced stability over the lifetime of the mattress. Choose from Gently supportive, Medium support or Firm support. The Heligan’s blend of wool and soft cotton in conjunction with “home grown” hemp are cleverly arranged to make one sleeping surface warm for winter and the other cool for summer to regulate your body all year round.