From top to bottom, each layer in the Coolvie 12-inch hybrid mattress was meticulously designed to move progressively from plush comfort to firm support. Designed with 3D soft knit fabric on the top cover, breathable and skin-friendly, cozy and cool, absorb moisture and balance body temperature. With 3-layers of CertiPUR-US certified different foam in the middle: top layer of open-cell increases ventilation and air flow foam, middle layer of comfy memory foam conforms to your body for targeted pressure relief, while high-density base foams ensure extra back support for optimal spinal alignment. And the thick base is made of Innovative 5-zone spring support systems, providing the targeted support to your body and complete motion isolation. Plus, strengthened edge support of this mattress increases your sleep surface, you do not worry to roll off or be ejected from the mattress.