Originally, it's a stereo specification, but only Right In, Right Out can be used. It works fine for mono use. I asked a local music store to repair it, but they couldn't because they didn't have a wiring diagram. I don't have the knowledge to repair it, but I think it's a very affordable item for someone who can. The main unit only, no box or adapter included. This price reflects the above, so please understand that it is a junk item before purchasing.