Features: The tuner features auto-tuning designed for automatically tuning for thumb piano. The tuning is from A1(55Hz) to C8(4186Hz) and A4 frequency is 440Hz. Built-in 3 backlight colors(red yellow and green) to indicate the condition of tone. LCD screen display for clear reading of the parameters. Compact size easy to carry and use in daily tuning. Specifications: Color: Black Material: Tuning: 12 equal temperament A4 Frequency: 440Hz Tuning : A1（55Hz）-C8(4186Hz) Package Size: 7 * 3.3 * 2.3cm / 2.76 * 1.30 * 0.91in Package Weight: 22g / 0.78oz Packing List: 1 * Tuner 1 * Sticky Glue