Dietrich Parts String Butler V3 Full Black, Hardware for Improving The Tuning Stability of Electric and Steel String Guitars, Designed for guitars with 3L/3R machine heads on the headstock, Corrects the position of the A, D, G, B strings for a straight course through the nut grooves, preventing the guitar strings from getting becoming stuck in the nut, Makes instruments more stable in tuning and more sustain-rich, Keeps the tuning of the strings even with very intense guitar playing (also copes with extreme bending), Quick and easy to build, Version V3 with minimum hole spacing 35 mm / maximum hole spacing 58 mm, Colour: Black@+*Note: * Not compatible with machine heads with impact sleeves / sockets!@+@+