Who makes Tune-o-matic bridges?
Gibson | Nashville Tune-o-matic Bridge.
How do you adjust a Gibson bridge?
Adjust Action on a Gibson Bridge
Measure the action at the 12th fret and determine whether you'd like to raise or lower the string height. Adjust the bridge height by turning the slot-head screw on the bridge post, or by whichever method would be applicable to your bridge style.