Nut and Saddle Sander
The nut and saddle sander is the fastest and surest way to perfectly square nuts and capos for them to be ready to be mounted.
The base of a nut or capo must be perfectly square and smooth. This is the only way it will be perfectly in contact with the bridge and therefore able to transmit the vibrations from the strings to the soundboard.
It is a unique tool that helps you maintain the nut or capo perfectly vertical while working with sandpaper, which is necessary to remove excess material and achieve the desired adjustments.
All of this is crucial for good sound.