Features: Tuner & Metronome & Tone Generator 3-in-1: the device is available for string instrument and wind instrument, mini and lightweight, easy to use. Practical & Professional: the tuner has Chromatic, Guitar, Bass, Violin, Ukulele tuning modes; the 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 lithium battery that leads to longer battery life, chargeable with Type-C port. Power Saving: if there is no signal input from MIC, or INPUT, either metronome or tone generator not work in 3 minutes, the machine will turn off automatically to save power. External Devices: the headphone or external amplifier can be connected via 3.5mm stereo jack. If headphone is connected, the speaker will no be sound output. Specifications: Material: ABS Connection: 6.35mm input jack, 3.5mm stereo output jack Power: 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 Pitch Range: 410~450Hz Frequency Range: A0(27.5Hz)~C8(4186.00Hz) Tuning Tolerance: ±0.5 cent Pickup Method: Microphone, pickup cable METRONOME: Tempo Range: 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)