Good flexible chair allows me to sit comfortably. Elbow rests are decent size not too large and fat that they can't go over the desk when the chair is too high. They are not able to slide left to right so they stay straight. The mesh is good for the back I can lean back easily without having to push too much and I can also lock the chair in a leaned position which is nice. There is a headrest that can be adjusted slightly to fit the back of your head if you are leaning back - I personally don't find it too useful it feels too bulky for me. All in All this chair was worth the purchase especially for my posture and ergonomics. I also had to buy an ergonomic keyboard due to typing for so many hours ( I am a developer). A good posture is totally worth it and this chair made is easy for me to have that posture which is having a positive difference in lower back pain.