Long established sliding mute which stays on the instrument.
Sliding fit, non rattling mute.
2 out of 2 found the following review helpful
Pros: It looks nicer than the Tourte mutes, and doesn't make any sound when you move it.
Cons: It killed a lot of the resonance of my cello when not in use so in the end I had to ditch it. Maybe it works differently with different instruments, but I wouldn't really recommend this.
good against wolf notes
Pros: On advice from a friend I bought this as a wolf note suppressor rather than a mute, and it does that job really well. I don't plan to use it as a mute as that would mean moving it and possibly losing the wolf note benefit!