Nut files are for maintaining the nut on your guitar. Filing the nut makes it smoother, which will help stabilize tuning.
*Not usable on double locking guitars.

4449EP1 Nut File 8-pc Set

file gauge (inch): 0.010, 0.013, 0.016, 0.024, 0.032, 0.036, 0.042 & 0.054

4449EP2 Nut File 8-pc Set

file gauge (inch): 0.009, 0.011, 0.026, 0.046, 0.065, 0.085, 0.105 & 0.135

4450-Fret File Set

file gauge (inch): 0.079, 0.098, 0.118

4451-Nut File Set

file gauge (inch): 0.012 & 0.032, 0.016 & 0.042, 0.025 & 0.052