Mechanical Metronome Music Universal Classic Electronic for Piano Drum Set Bass Violin Specification: Item Type: Mechanical Metronome Shell Material: ABS Movement Material: Plastic Steel Package List: 1 x Mechanical Metronome1 x Use Manual Note: According to the speed requirement of each song, move the to the corresponding speed scale, and pull the accent adjustment key to adjust the accent. For example:1. speed at 138 : move the metronome's to the position of the scale of 160 the is slower in the upward movement direction, faster in the downward direction2. Accent : 4/4 note: when the accent key is pulled to the 4/4 position, it will "ding" every 4 to remind you of the accent.