Musiclily Basic 10mm モダンギターペグナットセットアップ用 ボックス6角レンチ

Does the job. :)

Musiclily 10mm hex box wrench is what you need when you change the strings on your guitar. It took awhile before I realized that I needed to tighten up the nut on each tuning post periodically to prevent strings from slipping and going out of tune. The best time to do this is when you change strings. Just take the time to wipe down the guitar neck and body from any accumulated dirt. Then tighten the nuts until snug and put on your new string set.

This nut driver is a perfect fit to tighten the tuner nuts on all my guitars. Delivery was excellent.

Perfect

Wasn't wide enough for the nut on the jack for a squire affinty Strat or Telecaster