Check the listing for details. AKG K872 Closed-back Master Reference Headphones. Condition: Very Good - Refurbished. Listed at 1691.10 USD. AKG K872 master reference closed-back headphones set a new standard for performance. Custom 53mm transducers with 1.5 Tesla magnet systems yield unprecedented headroom, incredible stereo imaging, and extended dynamic range. The K872's open-mesh headband and 3D-shaped, slow-retention foam earcups mold around your head, creating a personalized fit. We couldn't believe how comfortable these headphones are - you can barely feel them! Yielding an exceptional frequency range of 5Hz-54kHz and unparalleled accuracy, these headphones are tailor-made for tracking, mixing, and mastering. And they provide excellent isolation. At Sweetwater, AKG K872 master reference closed-back headphones performed admirably in every situation we tested them in.