Bigger Size and Reliable Lumbar Support - The biggest chair in the price level. it comes with ergomomic office chair backrest with a reliable lumbar support will help you keep in a right position during long time working Breathable padding Seat - the padded mesh Seat is thick and resilient. Made of high Quality thick sponge and breathable mesh clothes, prevent body heat and keep your hip and legs sweat-free. Multifunction mechanism - pneumatic controls make it easier to raise or lower the Seat. The rocking mode can relax you from heavy work, pull out the handle to start rocking and pull it in to stop. This chair can support up to 270lbs.