I bought this to use with a 2box cymbal arm. I had a major problem with it initially. I couldnt put the cymbal arm into the hex hole and tighten it up to possition it where i wanted. if the thumb screw was attached, i couldnt push the arm through the hole, if i put the arm through the hole and then tried to tighten the thumb screw.. It would tighten enough and kept popping off. Happy to report that Thomann replaced the unit very quickly, the new one has a slighly longer bolt so thumb screw works perfectly.