Uses Chiropractic Spring Coil 2.34mm diameter as the mattress core connected in series through an automated production and enhanced with Steel Edge Support using fully heat-treated high carbon steel-engineered for maximum durability and firmly clinched with Steel Clips to provide increased firmness for seat edge strength, with engineered Flex Edge Supports on perimeter to create 23% greater usable sleeping surface and no-sag seating edge to extend mattress life, with hard-wearing Insulating Pad over the top of the coils securing it to the inner spring preventing the upholstery layers from cupping into the coil, deeper high density Extra Cushioning Layer and fully covered with Special Quality ‘Aerlan’ Fabric known for its softness and anti-bacterial characteristics with luxurious quilted designs to resist body impressions and provide surface comfort.