Mattress Layers: Stable Edge System 2” Comfort Soft Foam 2” Support Soft Foam 2” Support Soft Foam 1/2” Gel Memory Foam StabilityPlus Coil System CoreSupport Center: Reinforced Comfort Gel Foam in the center third for added support and durability where you need it most. StabilityPlus Coil: Independent coils target support and reduce motion transfer. Delivering comfort and support for years to come. StableEdge System: High-density, flexible border surrounding the mattress for better edge support, more usable sleeping surface and improved durability.