This dual-sided ultra-firm mattress allows you to choose between the firmest sleep experience available—or a medium-firm sleep experience. The choice is yours with just a flip of your mattress. This sleep surface is inspired by the minimalist approach to sleep found in places like East Asia, while including a more modern mattress design. Enjoy relief from back pain with a sleep surface that helps you achieve a neutral spine while also aiding proper blood circulation and better oxygen intake. The firmest mattress available, guaranteed. (Available with an optional sewn-on cooling cover from high-tech PE fibers.)