New in the box. The AKG circumaural M 80 MkII headphones are a semi-open circumaural design with a 1.57â€ driver. Features an adjustable headband, leatherette ear pads, and single-sided cable. 18Hz-20kHz frequency response offers deep bass and sparkling transients – excellent choice for home studio on a budget. With a $179 list price, these are a good buy at $49.99.