I have a Jaspers A frame three tier keyboard stand which I've managed to fill and was looking into buying an additional stand for my mixer and a drum machine when I noticed that Thomann also sold the Jaspers Monitor Holder and after a couple of quick measurements, I bought one to see if it could be used for this purpose.
The size and adjustability of the Jaspers Monitor Holder is perfect for my 12-channel home mixer and provides sufficient movement to position it ideally. I bought a second one for my drum machine, having been impressed with the build quality and performance of the first.
Assembly is easy and all hardware is provided - you simply fix the clamp, which separates into two halves, so you don't need to disassemble your the keyboard stand, slot in the bar on which the holders are fixed into the clamp and then tighten everything up with a hex key.
The holder is very sturdy and I've experienced no signs of it loosening and am confident that this will not change. The build quality is excellent and feels like a much more expensive piece of gear.
In summary, the holder is versatile, looks good and functions perfectly. Sadly, the hex key isn't included with the holder and this would have been a nice addition, but it wasn't a problem for me as it uses a standard metric hex key size and I still have the key from the stand.