Purchased a few years ago. I checked the operation for the listing. Both the 9V jack and battery work without any problems. Comes with the box and instruction manual. I couldn't find much information about it even after searching. There doesn't seem to be a website written on the back either. It says "Made in Japan," so it might be an original model from a musical instrument store or something made by an individual. The sound is a straightforward OD (overdrive). It doesn't have any particular characteristics, but maybe that's a good thing. It works well with any other effects pedal. It can be used as a booster or on its own. No claims, no returns. Feel free to negotiate the price. Please ask any questions in the comments.