Maybe I am the only one unlucky to get the stool with the wrong part, but I almost gave up assembling it. The metal ring that you see in the middle, in my case, was much much wider than the legs, so in order to fasten the ring to the legs, I had to apply unimaginable amounts of force while holding bolt and nut to squeeze them together and then somehow find a 3rd and 4th arms to fasten them. I used my legs to hold them together. I spent more than hour assembling it. Torture. Awful. Never ever I was that exhausted.
Once I managed it, the stool is very solid and stable. It even rotates. I was thinking that, IF I manage to assemble it, then any slightest thing I don't like about it, it goes straight to the box and shipped back. But despite the fact it gave me so much trouble and the fact that I wasn't able to normally play the guitar the next 36 hours due to arms hurting, I kept it to myself. I guess that alone goes to show that it is a good product, but the ring....