This is a vintage mechanical metronome, a product of Yamaha. Analog mechanical metronome. Portable design with a transparent cover (Largo Prestissmo) engraved on it. The pendulum is moved by the power of the mainspring, and that power is used to keep the tempo. There is rust on the horizontal lever under the needle and dirt on the lower left front (see photos). The main body has discoloration. Please understand that this is a used item. Height: Approximately 21.5 cm Width: 10 cm Depth: Approximately 9.5 cm No outer box.