Seat height adjusts from 17in. to 35in. to fit any task! 18in. range is great for multilevel worksurfaces. 1-touch pneumatic lift raises height up to 8in. - and a patented Wave Tube Extension that adds an additional 10in. to chair height! You'll sit comfortably at even the highest worksurface, for better posture, greater productivity and less fatigue. Adjustable back height prevents back strain. Perfect backup for your back! Chair back positions precisely for maximum support of your lumbar region. All it takes is a simple adjustment of the ergonomic knob controls to change backrest height. Adjustable seat back depth accommodates thighs. A simple adjustment of this chair's back depth accommodates the length of your thighs so your back stays in contact with backrest. Adjusted back depth helps prevent pressure on the backs of knees that might impact nerves under the legs. You'll sit more comfortably for longer. Solid steel frame is built to last. This economical chair has the strength of steel! It is sturdily constructed with a solid steel frame so you get years of dependable service. The 26in. diameter tubular steel base with 5-star legs has high-impact nylon glides for safety and stability. Cushioned seat and back are covered with black microcellular polyurethane for comfort and durability. Ergonomically correct footrest keeps you sitting right. Get just the right foot positioning with this chair's low-rung polypropylene footrest. It's designed to be ergonomically correct so you can position your feet and legs to relax thighs and calf muscles, reducing fatigue from sitting. Designed for multifunctional use. This chair is engineered for people who spend a majority of time at their workstations, and who need to adjust their seating positions as their tasks change. Meets or exceeds ANSI/BIFMA Performance Standards. Be confident in your purchase! You can rest assured your chair has met quality standards for safety and durability established by the American National St.