Turned on or off with the strings, the precision-ground surface works quickly and precisely to level the frets. Made of high quality aluminium alloy, CNC machining and good oxidation sandblasting treatments. They will balance most frets on the neck quickly and evenly. The length of 114 mm is very suitable for levelling problematic frets throughout the neck. It is also very suitable for creating the failure of the acoustic guitar. The length of 228mm is designed for smaller necks, such as ukuleles and mandolins. It is also suitable for full-size leveling. The neck and scene are leveled. 457 mm can easily balance the entire neck. The leveler allows you to level your frets under full tension without removing the strings. You can align your frets with strings on. Applicable to fret, saddle and fretboard grinding, great accessories for players and luthiers. Suitable for fret leveling electric guitar, acoustic guitar, electric bass, mandolin, etc.