The arms are different than what is in the manual. They do not turn in or slide forward. They can be adjusted up and down and for my size they fit fine without further adjusting.
I didn't like how large most chairs felt and I couldn't get the lumbar to hit me just right. I'm a small 5'0" 115 pound woman and this chair is perfect for me. So comfortable! I spend 8 hours in it without the back and neck pain I was getting from my old leather executive chair.
The chair assembled easily and all the mechanisms work well ( tilt raise & lower). The mesh seat and back are a bit too firm for me so I use a separate seat pad which works well. Overall the chair is great value.