Long established sliding mute which stays on the instrument. Fit by squeezing together the A&D strings and then push the mute down. The 2 strings when released will engage in the mute wires to secure it.
Keen Amateur
2
out of
4
found the following review helpful
Pros: I love these mutes for violin and viola. By varying the placement you can get a range of tones, ideal for fiddlers to accompany vocals. Easy to keep on the instrument but also easy to remove. I've got them on all my fiddles. Safe too, can safely shut the case. Much nicer to my ear than the alternatives.
Cons: Doesn't give the impression it will last for ever, the metal roller construction seems a bit flimsy. You might want a slightly quieter muted sound.
Teacher
Teacher