I found this chair to be uncomfortable after about an hour. I am 6ft tall and that may have something to do with it. I prefer a chair where the seat actually tilts down in front but these are hard to find without spending a fortune. This chair may be ok for some but didn't fit me. I ended up returning it.
The chair was easy to assemble with the provided allen wrench. Replacing an older similar chair. Definitely comfortable for a full day of working at my desk.
Love the chair! Especially the excellent lumbar support. Also love the mesh seat and back that provide great ventilation. Assembly was a snap with the absolutely fantastic assembly instructions! All screws/fasteners were color coded and in individual pouches for each step of the assembly! I've never seen a better assembly process!
After a year of ownership I had a problem with the chair cylinder. I inquired about the warranty and was sent a new chair. Great customer service. I was very glad for this outcome as I really like the chair and find it very comfortable.