Boss TU-3 Chromatic Pedal Tuner One of the world's top-selling stage tuners, the BOSS TU-2, has evolved and improved into the TU-3 pedal tuner. Housed in a tank-tough BOSS stompbox body, the TU-3 chromatic tuner features a smooth 21-segment LED meter with a High-Brightness mode that cuts through the harshest outdoor glare. Choose between Chromatic or Guitar/Bass tuning modes. Accu-Pitch Sign gives you pinpoint visual verification that tuning is complete. The BOSS TU-3 tuner incorporates a convenient Note Name Indicator that can display notes of 7-string guitars and 6-string basses, while the Flat-Tuning mode can support up to 6 half-steps. It's the kind of instrument pedal tuner that no performing guitarist or bass player should be without.