After assembling a 101 pieces. I should have stuck with my first instinct and sent this back. Chair is way too hard. Virtually next to impossible to line up the top and the bottom. If you're used to a regular office chair, this is not the one for you. No way to tilt back the top like a regular chair. Tried it for a couple hours. Don't think it would ever soften up. In order to return this year, I had to completely take it back apart, pack it up and pay for the return shipping. My cost to try out their chair about $50. My Comment on this chair. was free. Don't like it. Sorry will not buy another one without trying it first.