I am satisfied with this wolf eliminator, but it has a little problem for me:
I used it on a contralto nyckelharpa, I have to say that in my experience with this Gewa folf eliminator it's been not too easy to close it and fix it properly to eliminate the wolf. (But finally I did it!).
So I don't like too much the fact that it's difficult to fix it and avoid that it hits the bridge moving on the string, but surely, finally it works!