Details: The AT-300C is an easy clip-on tuner specifically designed for wind instruments & chromatic tuning. It features a two tone background screen, to aide with tuning. When the letter on the screen is green, the note is in tune. When it is white, the note is not in tune. The tuner has a detection range from A0(27.5Hz) - C8(4186.00Hz), and can be set to tune instruments in the following keys : C, F, B♭ & E♭. Powered by 1 x 2032 battery.