Housed in a tank-tough BOSS stompbox body, the TU-3 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, and enjoy visual pinpoint tuning verification with the Accu-Pitch Sign function. The TU-3 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 six half-steps. 

Tuning Range:

C0 (16.35 Hz)--C8 (4,186 Hz)

Modes:

Chromatic
Chromatic flat x2
Guitar
Guitar flat x2
Bass
Bass flat x3

Power Supply:

Carbon-zinc battery (9V, 6F22) or Alkaline battery (9V, 6LR61)
AC adaptor (sold separately)

Connectors:

INPUT jack
OUTPUT jack
BYPASS jack
DC IN jack
DC OUT jack

Current Draw:

20 mA (DC 9 V)
80 mA (DC 9 V, when High Brightness mode is on)