Each ERA Office Chair is built with comfort and durability in mind, and it all starts with our industry-leading all steel frame. The frame is the core of the chair, and therefore extensively detailed. All ERA Office Chair frames are built with heavy-duty 14-gauge steel tubing, with no plastic or wood framing like most office chairs use. The adjustable lumbar support is built into the frame. Steel spring cushioning is designed to make the user feel like they are floating in comfort, and also helps aid the longevity of the seat cushion. Each component that makes up and ERA Office Chair frame is top quality. At ERA, we simply would not have it any other way.