The BOSS TU-3S is a highly respected chromatic tuner, well-known among players for its consistent performance and durable design. This compact tuner delivers the same industry-standard functionality as the original TU-3 but in a more pedalboard-friendly form. The device features a 21-segment LED meter with adjustable brightness, ensuring visibility in various lighting conditions. One of its key features is the Accu-Pitch Sign function, which visually signals when tuning is complete. The pedal supports multiple tuning modes including Chromatic, Guitar, and Bass, accommodating a variety of instruments, even 7-string guitars and 6-string basses. It is powered via a PSA-series adapter and can even power up to seven BOSS compact effect pedals, making it a versatile addition to any setup.