Thank you for viewing. This is a KORG guitar/bass tuner. Perfect for practicing guitar or bass. I used it only a few times after purchasing it, but I'm selling it because I no longer use it. I have confirmed that it powers on, but I haven't checked the sound-related details because I don't have a guitar on hand. Please understand. Also, part of the LCD has a black burn-in (see photo 2). Model number: GA-20 Included: Instruction manual *No box Thank you.