This is the AKG K240 Studio, a semi-open-back studio monitor headphone. I bought it because it was well-regarded for its uncolored sound quality. I intended to use it for a long time, so I also purchased a 2-meter Mogami cable (blue 4φ: 5,000 yen) separately and was using that instead of the included original cable (black 3φ). Unfortunately, in my usage environment, the original cable didn't seem to match the impedance of my DAW audio interface, resulting in low sound pressure, so I gave up on using it. That's the only reason for selling it; there were no other problems (the Mogami cable increased the sound pressure). An unsigned warranty card is included. I used it for about six months, and it was always hung on the side of a rack, so there may be some dust that I couldn't completely remove, please understand. I'm selling it as-is.