itinlu Mini Clip-on Guitar Tuner with 360 Degree Rotatable Bright Display for Guitar Chromatic Bass Violin Ukulele Ideal for any guitar, chromatic instrument, bass, violin and ukulele player Adjustable view angle, the clip has been designed to allow the tuner to turn by 360 degrees Super bright backlight with LCD display, it provides excellent visibility Anti-interference, works on mechanical vibration sensor, allowing accurate tuning in noisy environments Power: 3v (cr2032 lithium battery) (included)