TonePros Metric Locking Tune-o-matic/Tailpiece Set (large posts) Gold Patented pinch freezes and solidifies your bridge and tailpiece Stays solidly set without movement Improves intonation, sustain, and tuning stability Mount on vintage instruments without marring or modification Stays in place with no wiggling so your guitar stays in tune better, has improved sustain, and harmonics will seem to jump out