Combining distinctive looks with pioneering ergonomics, Aeron performs like no other chair. It adapts naturally and adjusts precisely to fit people of all sizes and postures doing all kinds of activities, all day long. The imaginative design of both the work and side chairs gives superior comfort, body support, and style that are widely copied but never matched.Made largely of recycled materials, the Aeron chair is designed to last a long time, with parts that get the most wear easily replaced and recycled. Just what you would expect in a well thought-out design. The 12-Year Warranty covers everything that makes a Herman Miller Office Chair--including casters, tilts, pneumatic cylinders, and all moving mechanisms.