Features: Universal mechanical metronome suitable for most musical instruments such as guitar bass piano violin drum etc. Accurate rhythm clear and loud sound helping you improve your sense of beat and tempo suitable for musical instrument beginners. Easy to use wind it up first then your desired beat(2/3/4/6/0) and tempo(40-208 bpm) finally remove cover and set pendulum in motion. You can slide up or down weight on pendulum rod to adjust speed according to meter plate. Eco-friendly mechanical energy no battery or extra is needed; adopts a winding mechanism for to produce metrical . Traditional pyramid shape design with conservation cover durable ABS body and exquisite workmanship portable and safe to transport. Specifications: Color: Purple/Green//Black/Blue/Yellow(optional) Material: ABS + Metal : 2/3/4/6/0 Tempo: 40-208 bpm Item Size: 20.1 * 11.7 * 9.3cm/ 7.9 * 4.6 * 3.7in Item Weight: 560g/ 19.8oz Package Size: 24 * 12.3 * 11cm/ 9.4 * 4.8 * 4.3in Package Weight: 595g/ 21oz Package List: 1 * Metronome