The back of the chair is a bit loose and doesn't seem like there is a way to fix it. There is a small gap that causes it to move a bit. Other than that the chair is great.
I’m using this as a home office chair and it provides great back support. I’m 5’11” 220lbs and it fits me well. If I had one suggestion I’d ask them to make the seat just a tiny bit longer but the way it is now probably helps my back. Great chair.