These are simply the best speaker stands you can get.
Solid German engineering, made almost entirely of metal for robustness. They are mostly aluminium for light weight, but not at all flimsy. They are rated for speakers up to 50kg, which is a lot. Yes, they are dearer than budget stands made in China, but worth every penny, especially at Thomann's very competitive pricing. It's a case of buy the right thing once, rather than something that you will have to replace. They will last forever, and you can get spare parts if you manage to break anything. They are used by many high-end sound companies because of their quality. There really is no alternative.
I've been a sound engineer for years, so hopefully I know what I'm talking about. But look at the other reviews and you'll see others share my opinion.