23 Size B(medium) Herman Miller Aeron Classic Desk Chair. This is a chair that has been completely refurbished. That means it has been completely taken apart and checked for worn or broken parts and if found those parts were replaced with genuine Herman Miller Parts. It is in new working order and has been touched up so it is almost new again. There might be some very minor scratches on it but you would be hard pressed to tell it is used. It is the fully adjustable version with up and down, tilt forward controls, tilt back restrictor and adjustable arms up and down and in and out and has lumbar support. It is black for graphite color and the wheels work on hard and carpeted surfaces. This is a great chair. Don’t be fooled by sellers who call their chairs open box or display models. They are refurbished used chairs just like ours we just don’t try to mislead people. Open box does not mean they opened the box and put it back in the box like you would think. Just trying to help so you are not mislead.