A metronome makes regular audible ticks at a pre-set number of beats per minute. Battery operated metronome with digital input features speed adjustment from 40-250 BPM, beep sound, swing-out back, pocket size. Comes with 3V button cell battery (CR2032).A metronome makes regular audible ticks at a pre-set number of beats per minute. Battery operated metronome with digital input features speed adjustment from 40-250 BPM, beep sound, swing-out back, pocket size. Comes with 3V button cell battery (CR2032).