Features: Compact size clip-on tuner for chromatic/ guitar/ bass/ ukulele/ violin. One-button operation easy and convenient to use. LCD display 2 colors backlight: green- in tune white- out of tune. Rotatable design allows you to have the best viewing angle. For helping you to find the accurate tuning of your instrument. Specifications: Model: AT-01A Color: Black Tuning Items: Chromatic(C)/ Guitar(G)/ Bass(B)/ Ukulele(U)/ Violin(V) Pitch Range: 440Hz Tuning Accuracy: ±0.5 cent Power Supply: 1 * CR2032 Battery (not included) Item Weight: 18.5g / 0.7oz Package Size: 5.5 * 4.5 * 3.5cm / 2.2 * 1.7 * 1.4in Package Weight: 30g / 1.1oz Note: The instrument showed in the picture is not included. Package List: 1 * Tuner 1 * User Manual(English & Chinese)