The Royal Comfort Comforpedic 5-Zone Mattress In a Box (Double bed size) is designed to provide support, comfort and a better nights sleep. The Comforpedic Mattress uses the traditional bonnell-spring construction with several layers of high-density foam. The upper foam layers adjust to the shape of your body to provide a customised surface, while the lower bonnell spring layer offers pressure-relief and lasting support. Comforpedic Mattress will not only provide you with a more restful sleep, it's high quality construction and design surpasses other competing mattress brands.