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 lovers who play guitar piano drum guzheng and more. Features: electronic metronome provides beat type (0 to 9) beat speed control (40-208 /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 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 thumbwheel. A reliable practice partner for lovers who play guitar piano violin drum guzheng and more. Wonderful gift choice. Note: 1. Please remove batteries if you want to use USB cable to 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: Beat: 0 1 2 3 4 5 6 7 8 9 Tempo: 40-208 /minute Voice: Electronic Voice Human Voice Timer: 15min 30min 45min 60min 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)