This is a Herman Miller Classic Aeron, labeled as #B6. This chair is a 2015 model, it’s in excellent condition, like new condition. #B6 has been thoroughly tested, and is mechanically 100 % functional. Forward & backward tilt, adjustable lumbar, fully adjustable arms, mesh is in excellent condition & has like new resistance. Posture fit back support for an additional 50. Aeron headrest for 60. New Hardwood Floor castors for 20. New arm pads also available for 20. Please inspect every picture thoroughly, zoom in, zoom out, & don’t hesitate to ask any questions about the chair you are looking at. Because what you see is what you will get. Installation Video: Backrest will need to installed. Installation video on YouTube will be available, via shared link, upon request.