Sealy Posturepedic mattresses feature the Posturepedic CoreSupport Center, which provides additional support where you need it most. The center third of the mattress (the area that holds the heaviest part of your body) is power-packed to maximize support and enhance your bed-time needs. Some of our Posturepedics (Level "F" and higher) have Sealy Posturepedic's Titanium DSi innerspring. The Titanium DSi coil is a dual stage design that gives you conformance on the surface and deep-down support underneath. Coils are individually-wrapped for uninterrupted sleep next to your sleep partner.