Donner Dt-1 Chromatic Guitar Tuner Pedal True Bypass Chromatic which is suitable for wide range tuning LCD display leads clear results of tuning True bypass, real signal, no loss of tune Tuning range: a0(27.5Hz)~c8(4186hz) Tuning method: auto Notice :there is not power adapter included,you need to buy one Power Supply9V DC (Negative in the center). LED LightLED indicator shows the working state. LCD ScreenLCD display leads clear results of tuning. Input &amp; Output JackAnalogy though 1/4 mono audio jack. Full metal shellAluminum-alloy classic, stable and strong. True BypassTrue bypass for zero tone coloration.