This is a very good product for adding any generic sort of hook or holder to a vertical bar. The clamp grabs the bar well and does not slide.
I have added it to all my mic stands and use it as a cable holder for the mic when disconnected and / or moving to corner storage.
Docking off one star for a weird design decision for the attachment mechanism. The threaded rod retracts 4cm, but the metal "J"-shaped arch only leaves room for about 1cm rods. If it would have been a half-circle "C" arch it would have fit camera tripods or monitor stands. Right now it "only" fits mic stands and sheet note stands.
You won't get metal-on-metal scratches from this to your stands. The bottom of the "J" is padded, and the end of the threaded rod has a plastic head.
None of my holders have any sharp edges, no risk off nicking any headband material.
No cons, and cheap enough to get just to test it.