If you are serious about getting sleep, the SierraSleep® Loft and Madison 13-inch king mattress delivers comfort in numerous ways. An innovative foam called MemGel® Swirl provides superior support and comfort via its high density gel-infused memory foam. This is one of several layers of high density memory foam that contour to your body to provide pressure point relief and reduction of motion transfer. You'll love the cloud-like feel. Foundation\/box spring available, sold separately.