This is a Suhr buffer. It has a phase inversion switch, so you can adjust it to prevent phase cancellation when using it with two amplifiers. The appearance is relatively clean, but there are minor scratches as shown in the images. The back has Velcro attached over tape, so it can be removed cleanly. It occasionally stops producing sound, so I'm selling it as junk. It will probably be fixed with a circuit cleaning, but I don't have any time, so I bought a new one. Please purchase this only if you accept no returns/no claims.