Never able to get the wheels seated correctly. Finally removed the tension rings and inserted the wheels. If you pick up the chair they fall off. Other than that malfunction the chair is comfortable and works. OK for the price.
I'm 5'2" and my desk is high. I needed a chair that when raised up would put my eye level such that I don't keep tilting my head back to see (I wear bifocal glasses) the 24" monitor screen. (I also purchased a monitor arm that adjusts the height of the screen so it practically sits on the desk top.) When the chair is raised on the highest setting my feet do not touch the floor. But I can work without tilting my head and getting a sore neck. My husband made me a foot stool which helps with my feet. Like I mentioned the seat is very firm. My husband bought a different chair and the seat is like a mattress very soft but it doesn't raise high enough for line of sight to the monitor. On my chair if you sit back all the way it has good lumbar support and is tall enough to rest your head. The arm rest raises up if needed. Basically it's easy to put together it came with an L wrench for the bolts.