Features: tuner features auto-tuning designed for automatically tuning for thumb piano. tuning is from (55Hz) to C8(4186Hz) and A4 frequency is 440Hz. Built-in 3 backlight colors(red yellow and green) to indicate condition of tone. LCD screen display for clear reading of parameters. Compact size easy to carry and use in daily tuning. Specifications: Color: Black Material: Tuning: 12 equal temperament A4 Frequency: 440Hz Tuning : （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