Very shaky, poorly finished,

I have ordered this stool for my 11 year old son. At first, he looked good and seemed stable. That changed during assembly:
Usually, it's like this: you put the smaller Roht in the wider and both have holes through which you then put a screw and holds the whole. Not here.
First I had to find that the wider pipe has no hole, but only a recess. This means that the screw is fully inserted through the narrow tube and both are then simply placed in the wider. That said, if you then rotate the screw is not tight with all his might, can the stool not even just touch the seat and move away, because then only the seat in his hand. The rest stops.
Second, I realized that the smaller pipe is much too narrow. Although you can fix the pipe with a lot of power, so that the seat and stay tuned, but in the crossed axis wobbles the tube back and forth. I have then Gehofen with electrical tape, because the birthday was too close to appoint another seat.
Therefore, I can only advise against the purchase.