This is a Yamaha acoustic amplifier, the THR5A. I purchased it used and used it in my room, but I am selling it due to various circumstances. There is no noise such as crackling, and I think it is in good condition, looking clean. About half of the cushion on the back of the battery case lid has peeled off, but it's not noticeable unless you open the lid. I used it with batteries, but there were no problems caused by the peeling of the cushion. In addition to the main unit, an AC adapter, a USB cable, and the outer box are included. There is no instruction manual. I have confirmed the operation with batteries and the AC adapter, but I have not tested the USB output because I do not have the environment to do so. Thank you.