This task chair is attractive and comfortable. However, the caster wheels were very difficult to pop into the base and one wheel was almost impossible. I had to adjust the C-ring on that wheel's stem several times by pinching it a bit with pliers before it finally, finally could be installed. After that, assembly was easy, BUT the chair's adjustment feature does not work. I'm keeping the chair because, luckily, the seat height is fine for me. I did not call the manufacturer for assistance, but they do provide their customer service number in the chair's packaging.