I have swapped the chairs unfortunately. After a few weeks use the seat is broken and it projects a kind of wire on the right side outwards. It's just a matter of time until this reference pierces. Amazon side everything is as usual great. Delivery via Prime in two days. The replacement chair now comes also in a few days. Resending is not a problem because a package is then again available.
UPDATE: The Second Chair has held exactly one week longer. The looks from then unfortunately after a design error or just poor quality. I will now have to buy another chair.