Firm support doesn't have to mean stiff. The Cambridge Lux Firm pairs an 8-inch PowerEdge Elite fabric-wrapped spring system with high-density comfort foams and Energex hybrid foam - a material that blends the pressure relief of memory foam with the responsive feel of latex. A steel coil perimeter keeps the sleep surface consistent edge to edge, so you can use the whole mattress without that roll-off feeling. Up top, the E-Cool cover uses thermal comfort technology to absorb excess heat and keep temperature swings in check through the night. It's adjustable-base friendly, too, so it pairs beautifully with a power foundation. A great fit for back and stomach sleepers who want solid, cool, long-lasting support.