Equivalent of 1600 pocketed springs in a king-size mattress. Available as a firm edge pocket divan set or firm edge pocket base on tapered legs set. Therma-Phase TM Ultra is a unique pressure relieving material, infused with patented phase-change crystals, plus copper and precious metal micro-beads. The phase-change crystals work by constantly absorbing and releasing body heat to maintain the ideal sleep surface temperature. The infusion of copper and precious metal micro-beads works as a super-fast heat conductor, quickly moving heat to and from the mattress surface as required.