Violin Black 2 Prong String Adjuster - 4/4 to 3/4 Size

I bought 7 of these to add to 2 student violins that didn't have fine tuners on all the strings to make it easier for my students to tune. After installing the first one, I was disappointed to find that the Dominant string with ball end DID NOT FIT through
the slot at the end of the fine tuner. The online recommendation in one of the Q & A's to use a tool to widen the slot did just that, but there's a groove at the bottom that the string needs to settle into that CANNOT be widened. I took the fine tuner off
the instrument and put the string back on without a fine tuner. I'm not sure what the solution is now.

Dear Sharmusic, let me call things the way they are: maybe it's time to realize that there are two kinds of fine tuners for violins produced by Wittner. Narrow for E string and wide open for A D and G. It's unprofessional, telling customers about "professional
violinists" using finer tuners only for E string, as a explanation for not having in stock those wide open. Or telling them to open narrow fine tuner ( made for E string only) with some tool, which looks ugly, uneven an cheap. Go to Wittner website finally
and get those wide open fine tuners for gut strings.