The chair back assembly does not fit properly into the support per the directions thus the chair back wobbles and does not provide adequate support. In hindsight I would have spent more to purchase a better quality chair; you get what you pay for.
I am very pleased with this chair. It is comfortable good looking and I like the ergonomic design. It swivels and rolls smoothly. It also looks good; like one of those expense chairs. My only issue is the chair is not tall enough to raise me up high enough to use my keyboard at the correct angle. (My wrists should be below my elbows.) My desk is too tall. I love the chair but now I need to replace the desk. My advice: When you buy a chair aside from sitting in it know how high the seat must be so your arms are at the correct angle for typing on a keyboard.