Serta Works Ergonomic Executive Office Chair with Back in Motion Technology, Black Bonded Leather Back in Motion Technology pivots the lower back forward to flex pelvis and keep your back in a positive neutral position Thick, ergo layered body pillows, cushioned headrest and padded arms are comfortable and supportive Ergonomic armrest, height and seat adjustment makes it easy to find - and lock - the most comfortable positions Supple bonded leather or soft fabric upholstery give any workstation an instant upgrade Some assembly required