This is my new favorite tool to use I used to do the old school way by tracing the box end on a sheet of paper cutting it out folding it a few times find your center line this makes it so much easier and faster and is a great price !

I got the center finding ruler a few months back even though I already had one. Divisions to 16th on regular side and 32nds on centering side help with precision and accuracy. I use it with centering neck to boxes, spacing tunes and centering fret and side markers. It is a quality tool that I now use on a regular basis.