G-Craft MH-150L 3x3 Machine Head Locking Tuner for Guitar
The MH-150L is a set of Locking Machine Heads for acoustic or electric guitar that uses three per side tuners. It has a contemporary mini buttons and is finished in black. It is mounted with 45-degree screw and will fit most headstock and others with few adjustment (check your guitar tech to be sure). Check the pictures for dimensions as well.
HOW to and WHY USE LOCKING TUNERS?
Locking tuners have clamping mechanism to lock the string in place. In the case of the MH-150L, the string is locked in place when the thumbscrew on the casing is tightened.
This has two advantages: First, by locking the string against the tuner, you can use fewer string windings to keep the tuning stable. Less windings generally means quicker and easier restringing. But the main advantage of locking tuners is with tremolo-equipped guitars. By locking the strings to the tuner, this reduces the amount of string slippage due to use of the tremolo bar and results in reduced tuning problems resulting from tremolo use.
Please also note that nut/saddles and setup also affects tuning stability so please check these as well.