Mellow 7.5-inch bifold box spring provides the look and functionality of a traditional box spring with longer-lasting stability made from sturdy， durable steel. Often times， a traditional foundation is not always the most convenient solution. The unique bifold design makes this box spring the perfect solution， offering the sturdy support expected of a standard foundation with the utmost ease of mobility. It is constructed with heavy gauge metal for maximum support and durability. Set up in no time， no assembly required. Simply unfold， zip up the cover and place it on your bed frame. All Mellow box springs come with a 5-year manufacturer’s warranty.