Haven mattress company, makers of the 10" Rejuvenate is the first direct to customer mattress to be certified by the Canadian Chiropractic Association. The CCA recognizes the unique zoned support layers of the Haven as a significant advantage to spine health. The firmness in key areas pushes up and support heavier parts of the body. In combination with more flexible foams that allow for contouring of hips and shoulders to maximizes sleepers comfort. Haven's unique approach to ergonomically zoned areas allows for proper spine alignment. An aligned spine can relax and rejuvenate properly, improving sleep quality and overall health.