Features: Tuner & Metronome & Tone Generator 3-in-1: device is available for string instrument and wind instrument and lightweight easy to use. Practical & Professional: tuner has Chromatic Guitar Bass Violin Ukulele tuning modes; metronome has Chinese / English voice counting-beat and TAP tempo function. 2.5-inch Digital Display: large AV color screen is clear and easy to read. Built-in 3.7V 600mA Li-ion Battery: polymer battery that leads to longer battery chargeable with Type-C port. Saving: if there is no signal input from MIC or INPUT either metronome or tone generator not work in 3 minutes machine will turn off automatically to save . External Devices: headphone or external amplifier can be connected via 3.5mm stereo jack. If headphone is connected speaker will no be sound output. Specifications: Material: ABS Connection: 6.35mm input jack 3.5mm stereo output jack : 3.7V 600mA Li battery Charging Time: <2H Working Time: ≥5H Item Size: 107 * 72 * 20mm / 4.21 * 2.83 * 0.79in Item Weight: 161g / 5.68oz Package Weight: 185g / 6.54oz Package Size: 14 * 8.8 * 2.8cm / 5.51 * 3.46 * 1.10in TUNER: Tuning Mode: Chromatic Guitar Bass Violin Ukulele : 410~450Hz Frequency : A0(27.5Hz)~C8(4186.00Hz) Tuning Tolerance: ±0.5 cent Pickup Method: Microphone pickup cable METRONOME: Tempo : 30~260bpm Beat: 0 1 2 3 4 5 6 7 8 9 Voice Beat: Chinese English Package List: 1 * Tuner 1 * Pickup Cable 1 * Type-C Cable 1 * Manual (English)