The Hermann Miller Aeron is the ultimate ergonomic office chair, chosen by the best employee friendly companies. Instead of a solid seat and chair back, there are instead fiber mesh fabrics that are breathable and form-fitting. It distributes your weight evenly and minimizes pressure. The chair has a high and wide contoured back, designed to take pressure off the lower spine and a waterfall front edge to reduce pressure under the thighs. The chair is fully adjustable (specific adjustments vary according to chair model): seat height; seat tilt, so you can have a chair that moves smoothly with you as you want it to, allowing for correct support in all positions; tilt tension, so the chair will move as easily as you want it to; tilt limiter; extra lumbar and posture supports; and arm height and angle, so that whether you are working directly in front of you or reaching to the side, your arm can be supported. It even comes in 3 sizes, so that whether you are tiny or large there is one to fit you.