The Sealy® StableSupport™ Foundation has been engineered to provide the ideal surface for Sealy® mattresses. The solid, flat construction ensures your bed will maintain its comfort and support for years to come, while a high-quality navy fabric complements the overall aesthetics of every Sealy® mattress. This 9" height matches a traditional box spring, tested for durability and covered by a 10-year limited warranty from Sealy®.