Buy at www.musicianscart.com Tomsline Mini Pedal Tuner AT-07,Connect a DC 9V power into the pedal,Link the input, and turn on the tuner by pressing on ON/OFF button, If you want to change the pitch, then press A4 button. The pitch ranges from 430Hz to 450Hz.,If you want to tune by note flat, press Flat button. Flats offer 4 steps: b, bb, bbb, bbbb.,Play a single note from your guitar, the note name will appear in the tuner screen. The screen color will change, and the tuning needle will move.,The center blue tuning meter appears, and 2 blue triangles appear: note in tune.,The left red tuning meters appear, and the left blue triangle appears: flat note,The right yellow tuning meters appear, and the right blue triangle appears: sharp note.,The tuner has bypass function. When tuning finished, press ON/OFF button, the original guitar signal will get through without any distortion.