The innerspring coil unit is the base of the mattress. It allows even distribution of your body weight while you sleep. The innerspring is steel so it will hold its strength for many years. The coils are what support your body in places where you need it most.
A box spring or foundation is an important part of the sleep system. A mattress and box springs are designed, tested and proven to work together. It’s not the mattress alone, but the total sleep set that is designed to provide to provide proper support, especially for the new non-flip mattresses. Most sleep sets are designed to work with a particular style box spring or foundation. A proper foundation or box spring will properly support your mattress and improve the overall durability of your sleep set.