I originally gave the Sunpan Modern Quinn Office Chair a 5 star review. It's attractive and sturdy, and unlike the previous reviewer, I find the seat comfortable. Unfortunately, the lift mechanism is defective. At first I thought the problem was the pneumatic cylinder, but after several failed I isolated the problem to the lever that depresses the button on top of the cylinder. By removing the lever I was able to set the chair to the proper height. I've uploaded a photo showing the mechanism. (Pardon the dust.) By lifting the tabs with pliers and unscrewing the plastic handle at the other end you can remove the lever. Depress the button at the top of the cylinder and push the cylinder down to your preferred seat height. Release the button and the cylinder maintains the proper height. Unfortunately resetting the height involves the inconvenience of partially disassembling the chair -- hence a rating of two stars.We really like the chair but we ordered two and only one chair was delivered, our order says the other chair is running a bit late but its been over a month now and it shows that both chairs have been delivered. I cannot find where I complain to to get the other chair. Very frustrating.Very uncomfortable chairs. Look nice but not comfortable at all