Atop this solid base is a complex system of springs, foam and one continuous steel rod to support the entire structure. The intricate arrangement of springs includes the ultimate flexible lumbar spring in the Plus™ System, which cradles the back, neck and head for the optimal support in any recline position. The single steel rod base is created with a unique cold bending process. The process is more difficult, but it makes the product more durable.Next, we layer foam to create the softest, most conforming seat possible. Our Comfort-Zones™ foam is molded directly over the steel base with perforations that ensure identical air pockets. This consistency ensures the foam’s ventilation and a long lasting cushion. Two more layers of foam are fashioned above that to ensure the seat is protected and fully functional.