Grover Rotomatic Guitar Tuners Chrome Mini Buttons Locking 6 on a Side

Grover Rotomatic Guitar Tuners Chrome Mini Buttons Locking  6 on a Side 

Rotomatic® tuners that automatically lock the string as you tune. For 6-in-line pegheads.

Internal-cam locking string posts and 18:1 fine tuning are built into Rotomatic midsize cast housings to fit 6-in-line pegheads. As you tune, the post automatically locks the string. You’ll need fewer string wraps, change strings faster, and your tremolo will have more accurate return-to-pitch.