Used for e-cymbal
I used this to attach a Yamaha e-cymbal to my stand. It worked perfectly, and the cymbal is steady and in the correct position. The washer and limiter that hinders the cymbal to rotate was easily mounted.
The clamp fits barely onto a 38mm Roland stand. There are just a few threads connecting, but enough to keep the arm in place in my home setup. I wouldn't recommend it for heavier cymbals or touring when mounted on 38mm.
This can be solved by using another clamp, better designed for 38mm. Or by replacing the bolts with longer bolts.
I recommend this arm for e-cymbals.