Boss AD-2 acoustic guitar preamp. I purchased this used and only used it indoors, but I am selling it due to various circumstances. It works without any problems. The knobs also work without any scratchiness. I haven't been able to confirm the line out because I don't have a cable for it. The normal output works fine. Operation has been confirmed with both batteries and an AC adapter. The label on the back was peeling off from when I bought it, so I'm selling it at a bargain price. This listing is for the unit only. Thank you. Type: Acoustic Guitar Manufacturer: BOSS