286812 Feature: orange and green dual color backlight， 360 degree swivel， multi-angle adjustable view angle， small shape， easy operation Tuning objects: C ( twelve-tone equal temperament )， g ( guitar )， B ( bass )， V ( violin )， W ( wind music ) Color: black Size: about 89 x 53 x 18.5 mm A4 frequency range: 430HZ-450Hz Pickup method: pick up by clipping it on the musical instrument Tuning mode: auto tuning Guitar accompanying sound reduction way: b， bb Wind music tuning: C， F， Bb， Eb Power supply mode: 1 x Button battery CR2032 ( not provided ) 1 x Tuner 1 x English user manual In original package