Neewer NW-707 Traditional Wind Up Mechanical Metronome for Piano Guitar Bass Drum Violin and Other Musical Instruments (Black) Perfect practice tool to produce regular, metrical beats to help you play rhythms accurately Improve your sense of beat and tempo No battery is needed. Neewer mechanical metronome uses a winding mechanism for power to produce metrical beats. Beat selection is: 0, 2, 3, 4, 6 Produce a clear and loud sound for use when practicing piano, violin, guitar, bass, drums and other musical instruments The pendulum offers great visual tempo cues which makes it perfect for beginners learning difficult passages