Schaller Roller Bridge, Chrome A direct replacement for most Tune-o-matic style bridges!Schaller's unique variation of the Tune-o-matic bridge features low-friction roller saddles for smoother tuning and tremolo action.These intonation-adjustable brass saddles allow adjustable string spread, and are angled slightly for correct alignment with the offset mounting studs and threaded bushings. The bridge is compatible with standard Gibson guitar tailpieces. Use a 1/4" drill bit to install the bushings. About bridge & tailpiece measurements String spread is the distance between the centers of the outer strings on a bridge or tailpiece.Saddle radius determines the arc formed by all the individual saddle heights, and is similar to the measurement of a fretboard.Stud/post spacing is the distance between the centers of the mounting posts of a bridge or 'stop' tailpiece.Positioning the bridgeFind bridge placement for any scale with our free online tool fret position calculator.