The KORG MA-1 metronome is a compact device with tempo adjustment and rhythm functions. - Brand: KORG - Model: MA-1 - Color: Blue - Functions: Tempo adjustment, volume adjustment, rhythm function - Port: Headphone jack - Buttons: Start/Stop, Tempo/Tap button Operation has been confirmed. Dry batteries are not included. There is no corrosion on the battery contacts. As it is a used item, there may be some minor scratches and dirt.