Do you have a question about the Flanger FT-12A and is the answer not in the manual?
LCD display shows tuning information.
Clip is used to attach the tuner to the instrument.
Power button is for power on/off and tuning item switching.
A4 adjust button is for setting A4 pitch reference.
Long press ITEM/ key to turn on/off.
Press A4 adjust button to set A4 pitch reference.
Short press ITEM/ key to switch tuning items.
Backlight indicates tuning status: green for in tune, orange for sharp/flat.
Replace battery when LCD or backlight dims.
Avoid high temperature, humidity, or subzero environments.
Avoid direct sunlight, do not disassemble, keep manual.