Tri-Zone Pocket Coil System – Includes 3 zones of support at 1102 coils (head/torso/foot) with thick 2-mm spring coils for extra lumbar support in the torso zone. Foam Encased Edge Guard – 4-inch hard foam perimeter for added edge/sitting support, with a ½-inch quilted border. Tight Top Comfort – 3-cm latex and 3-cm gel layered tight top. 3-inch medium soft foam and double fiber pad for added lumbar support. Bamboo Woven Fabric – Stretchable bamboo woven fibers with embossed pattern for natural comfort and breathability.