Andoer LED Auto Clip Chromatic Digital Tuner, for Guitar/Bass/Violin/Ukulele Tuner Turning 360 degree freely. Adjustable view angle. An extra large LCD screen, red and green blacklight. Super anti-interference. Handy compact digital clip-on style. Tuner pick up the sound by vibration. Easy to clip onto any stringed instrument. Sensitive and stable. Tuning Pitch Indicator Light: In flat: Indicator to the left and LCD screen turns red; In sharp: Indicator to the right and LCD screen turns red; In tune: Indicator to the middle and LCD screen turns green.