Balanced Comfort. The mattress you’ve been waiting for, Serta’s Landing Manor Perfect Sleeper King mattress combines advanced technology with ultimate comfort. The world’s first memory foam, Cool Action, is infused with the support and cooling touch of Serta’s MicroSupport gel. This revolutionary gel memory foam is designed to deliver excellent pressure relief and targeted support while reducing heat build-up at the sleep surface. Cool Balance technology combines high-performance, heat- and moisture-regulating fabric that helps promote airflow, offering a comfortable, balanced sleep temperature. EverCool Plus Memory Foam unique’s open-cell structure dissipates heat away from the sleep surface, relieving pressure points that cause tossing and turning. Topping this magnificent mattress off is Serta’s PillowSoft Foam, an extra-soft layer of comfort that gently contours the body to provide enhanced cushioning.