Buy or not buy is the question ...

The installation manual is a joke - even if the chair would cost only 50 EUR. A bad copy and for Schriftgroesse you need almost a magnifying glass. It lacks the very important indication of how to mount the rollers. That's tricky, because these incl. The Befestigungshüsen consist of hard plastic. For driving you have to hit directly on the role underside - only rubber mallet and gently !! - Make sure that the fastening sleeves and do not tilt otherwise there is a guaranteed installation damage ... This procedure is not described. Since the pre-assembly of the rolls would mean no packaging factory change, this situation is all the more annoying.
Therefore, in advance a maximum 3 stars.
The instructions for installing the armrests is not much better and to determine which is the rear or front, I had to call the product image from Amazon ...

To chair itself:

I think you have to look at the evaluation function for the price,
ie for the MSRP of 239 EUR, the evaluation of the price / performance ratio to be spotty.

I bought the chair for 89 EUR at Amazon - thus already provides for the assessment of different again:

Adjustment / settings:
well - the Syncroeinstellung (parallel variation of the inclination of the seat and backrest perhaps not for everyone is ...).
The best sample sit real before buy ...

Upholstery:
Angenehem - provides support and prevents pressure points.
I can make no statement about the durability after a few weeks.

Efficiency:
As a full-day use I would not choose the chair, but for three or four hours in the home office he is well.

Personal conclusion:
For max. 90 EUR I would buy the chair back