Tuning Guide Indicators; Mode Select Switch - Boss TU-2 Chromatic Tuner Owner's Manual

5. Tuning guide indicators

These will light to roughly indicate the tun-
ing.
10
The pitch is flat
The pitch is sharp
The pitch is correct
(within +/-3 cents)

6. MODE select switch

This switch changes the tuning mode.
When this switch is first pressed, the meter
will blink to indicate the current mode.
If you press the switch again, the meter will
cycle through the following modes, and the
corresponding indicator will light.
Bass Double Flat
Bass Flat
Bass Chromatic
Guitar
Guitar Flat
Guitar Double Flat