The back support is okay but you cannot lock the wheels and the chair spins around at will unless your feet are on the ground. Okay chair in a pinch but I would recommend spending a little more for a chair with the lock features.
The chair I Purchased is great. The only thing I do not like about it is that it has no variable tilt positions. It is either locked in the fully tilted position or locked in the fully upright position (no in between tilts). Other then that the chair is great.
The chair was easy to assemble and came with the tool necessary to put it together. The assembly instruction booklet was easy to understand (all pictures no text). The pieces were all labeled and were group accordingly. Easy peasy!
I purchased this chair for work and could not be more pleased! It is very comfortable and the perfect height for my work setup. Plus its a great value for the quality. I'd highly recommend this chair.