Which Tone-Lock™ (tailpiece studs and spacers) is right for my guitar?

If your guitar is a USA made Gibson®, you definitely need the INCH Tone-Lock™. If your guitar is made anywhere other than the USA, you need METRIC Tone-Lock™. For other guitars made in USA, there is always the possibility that the builder used METRIC studs/inserts on the guitar, as both INCH and METRIC studs and inserts are readily available in the U.S. For any guitar other than a USA made Gibson®, or an imported guitar, please consult the builder about the thread size of the tailpiece inserts. Faber® Tone-Lock™ studs sizes are: for Gibson® guitars, 5/16-24; for imported guitars, 8Mx1.25. If you are interested in a Tone-Lock™ KIT or a Tone-Lock™ MASTER KIT, the same information applies, as only the Tone-Lock™ stud type is used to determine whether you need an INCH or METRIC kit.