Mberg Fine Tuner
Ultra Light Mberg Titanium String Adjuster is designed for violin E and viola A strings with ball ends (not for use with the lower strings). Lightweight design and materials will not dampen the vibrations of the tailpiece.
I think these are likely the best available. Incredibly smooth...
I don't know why I waited this long to get this tuner for my viola, but it is worth every cent. The ease of string installation, the security at the end, and the smooth turning mechanism and precise adjustment are second to none.
This is the finest quality fine tuner available. The others are more common but do not perform as well. To me it is absolutely worth a little more money.
I am impressed! There is added smoothness for both violin and viola along with a nice fullness on the violin e string. It added refinement that I didn’t expect. I will recommend it to my students.