The Stanhope St. William uses state of the art design and Technology. A smooth top hybrid design featuring an individual wrapped spring support system. The mattress delivers deep conforming comfort and elimination of surface transfer. As a smooth top hybrid mattress, the thoughtful layering of high-density foam support layers affords maximum support and comfortability. A cool to the touch circular stretch cover provides cooling, support and motion separation between sleepers. The addition of Embrace Foam allow the bed to conform around your body. The addition of Gel Shade Foam provides both cooling and support to provide a great night sleep. This group includes Twin XL mattress and foundation.