hydraulic

Extra large comfortable seat: Diameter of 14.8″, generous 4.5” cushion is fully padded by high-density soft sponge for all day comfort.
Easy operation:You can easily adjust the seat height by hand lever,height range from 22.4 inches to 30.3 inches,meet varying heights and applications.Makes it easier to get through a busy day, very convenient for multi-tasking work.
The exclusive Molded foam is specially molded around the seat base,Thicker and softer seat provide extra comfort. Premier thicker PVC leather, elegant stitching even for the bottom side of the seat.