Qzoxx Et All Instrument Clip-on Chromatic Tuner Tuning scale:Chromatic, Guitar, Bass, Violin, Ukulele the color change to Green when in tuning Tuning mode: Vibration Tuning range: A0 (27.50 Hz) - C8 (4186 Hz) Precision:  1 cent; Response Time: &lt;20 ms Power: 3V (CR2033 Lithium