The Tune-a-matic/Stopbar bridge is standard on most Gibson guitars. In this system the strings are threaded through the back of the Stopbar. The strings are then placed onto the saddles of the bridge which have grooves for each string. The bridge part of this setup is called the Tune-a-matic. The height of the bridge can be adjusted via two thumb wheels. The intonation can be adjusted via screws which are located on each saddle. There is another method for Tune-a-matics where the Stopbar isn’t used and the strings are strung through the guitars body.