Digital metronome tuner for Chromatic/Guitar/Bass/Ukulele/ViolinTwo-clor Backlight Screen:Green-in tune,white-out of tune. Package List:2 x AAA Battery 1 x Chromatic Tuner1 x Piezo pickup Specifications TUNER Tuning items: Chromatic, Guitar, Bass, Ukulele, Violin Detection range: A0(27.5Hz)-C8(4186Hz) Pitch range: 430Hz-450Hz Tuning accuracy: ±0.5 cent METRONOME Tempo range: 30bpm-260bpm Beats: 1, 2, 3, 4, 5, 6, 7, 8, 9 If there is no signal inputs in 3 minutes after the power is on, the AMT-560 will turn off automatically. Precautions: Avoid use in direct sunlinght,extreme temperature or humidity,excessive dust,dirt or vibration or close to magnetic fields. Be sure to power off the unit when not in use and remove the battery for extended periods of inactivity. Radios and televisions placed nearby may experience reception interference. For cleaning,wipe a clean, dry cloth.Do not use flammable liquid cleaners such as banzene or thinner.