Yamaha QY100 handheld sound module. This listing is for the main unit only. Internal battery has been replaced. This is a used item, so there may be some scratches and marks, but it is in relatively good condition. The LCD screen is also clean. I have tested the demo data playback with my own power adapter (please note that the adapter is not included) and confirmed the sound through headphones. I have also confirmed the operation of the front buttons. Battery operation has also been tested and confirmed (batteries are not included). Other operations have not been confirmed. I do not have detailed knowledge of the equipment, so I may not be able to answer detailed questions. Please be aware that this is a used item and will have some wear and tear. I have checked the item generally, but there may be some oversights. Please forgive me if there are any. Please only purchase if you understand that this is a vintage used item. Please be aware that I cannot accept claims after delivery. I do not ship overseas.