The chair is unacceptable. In 3 years, the backrest adjustment mechanism has broken, the mechanism that stabilizes the headrest has failed, and the armrests have always moved "around" on their own.
Even when new, the chair created quite a few problems. If you don't know how to adjust it properly for your body (it has many adjustment points), it doesn't support the lower back at all, resulting in pain in the lower part of my spine (making a previous issue even more intense). I had to search for guides and reviews to adjust it correctly, and it took me several days to manage not to be in pain.
If someone tries to sell you this particular chair, stay away. They do not have your best interests at heart, and any other suggestion after this is suspicious.

Finally, after quite a bit of pressure from my side, they agreed to send someone to repair it, one of their employees from Athens. He came, removed the old shock absorber with great difficulty, banging it and making marks and dents underneath, and installed the replacement shock absorber. Since then, it has not broken again. So I am increasing the rating by one star, since at least after months they responded.
---------------------
I’m coming back with a new comment:
After four months, the chair’s shock absorber broke, causing it to lower itself all of a sudden. I spoke with the company and the only thing they can do is send a replacement shock absorber. They do not have technicians or any partner in Attica, and I will have to do the repair myself. They also did not send me any instructions on how to carry out the replacement. In the end, after my email, they called me to tell me roughly what tools I need and how I would do the repair myself. THEREFORE the warranty is fake and they do not provide service. If I had known, I would not have bought it. UNACCEPTABLE for a chair worth over 600 euros to have its shock absorber break so quickly, when I had a cheap Chinese one for 10 years without the slightest issue. UNACCEPTABLE that there is no warranty support. Therefore, one star for the serious defect it developed, as well as the lack of support from the company.
----------------------------------------------------------------------------
A fantastically comfortable and sturdy chair with a wide range of adjustments so it can adapt to all body types. It assembles in 10-15 minutes very easily, and the package includes all the necessary tools required. The back height is adjustable, the armrests move in 4 directions, the upper back angle is adjustable, and the headrest is adjustable in 3 directions. The rolling is quiet and comfortable, and overall it is very sturdy without creaking. The mesh is strong and durable and conforms to the body. By adjusting all of the above, you create the ultimate comfortable chair that supports every part of the body as it should, whether you want to sit slightly forward to type, in relax mode, or somewhere in between.