The electronic metronome Features digital display, beat speed control, volume control, battery or USB powered, non-slip bottom and more functions. It " s a reliable practice partner for music lovers who play guitar, piano, drum, guzheng and more. Features: The electronic metronome provides beat type (0 to 9), beat speed control (40-208 beats/min), electronic and human voice, timer (15/ 30/ 45/ 60min). Digital display for easy reading, clear at a glance. 3 AAA batteries (not included) or Type-C USB cable powered, more humanized. Easy to use via the control buttons and a large turntable; compact and lightweight, convenient to carry. With earphone jack for silent use, not disturbing others; supports volume adjustment through the thumbwheel. A reliable practice partner for music lovers who play guitar, piano, violin, drum, guzheng and more. Wonderful gift choice. Note: 1. Please remove the batteries if you want to use USB cable to power it. 2. Size and color may be slightly different due to manual measurement and different light conditions. Thanks for understanding. Specifications: Color: Black/ White/ Light Blue/ Light Purple (Optional) Material: Plastic Beat: 0, 1, 2, 3, 4, 5, 6, 7, 8, 9 Tempo: 40-208 Beats/minute Voice: Electronic Voice, Human Voice Timer: 15min, 30min, 45min, 60min Power Supply: 3 * AAA (not included) or Type-C USB Powered Item Size: 140 * 70 * 45mm / 5.51 * 2.76 * 1.77in Item Weight (without battery): 130g / 4.57oz Package Size: 14.5 * 8 * 5cm / 5.71 * 3.15 * 1.97in Package Weight: 175g / 6.17oz Package List: 1 * Electronic Metronome 1 * USB Cable (Type-C) 1 * User Manual (English)