The walnut, mat silk 813M Metronome from Wittner is a triangular-shaped windp metronome with a swinging pendulum to mark time. It can be used by musicians and students for applications such as sight-reading, rehearsals, ensemble playing, and more. The 813M metronome features an audible click with a bell on the downbeat. It has a snap-on cover and an adjustable weight on the pendulum. The range is selectable from 40 to 208 BPM (Beats Per Minute).