The TU100 gives you 7 different tuning modes, including Regular, Flat, Double Flat and Chromatic mode. A precise 7-segment LED and 11-point Stream Meter guarantee accurate tuning. You can adjust the reference tone in the range between 438 and 447 Hz, plus there is a mute function for silent tuning. We have also included a status LED for effect On/Off and battery check, and you can run your TU100 on a 9 V battery or a DC power supply (not included). For absolutely noise-free operation, a first-class electronic On/Off switch is integrated.