This is a simple theremin, an original from Ishibashi Gakki. I bought it at a musical instrument store when it was released because I like Cornelius. I haven't used it much, only a few times. Please note that I haven't been able to confirm its functionality with an amplifier because I don't have one currently. The sponge in the battery holder is missing. I've disposed of the box, so it's just the theremin itself. The serial number sticker has also been removed. It has been stored at home and hasn't been used for many years, so I'm selling it as a junk item. Please refrain from purchasing if you are a perfectionist or are overly concerned about condition. A theremin with simple controls for adjusting the tone. - Model Name: THEREMIN - Output Adjustment: Volume adjustment knob - Frequency Adjustment: Frequency adjustment knob - Country of Manufacture: Japan - Brand: Ishibashi