HD 600 is the benchmark reference headphone for enjoying your hi-fi setup. Foundation of transducer system is an acoustically transparent open-back earcup. 42mm Driver is free from turbulence and distortion. 38mm Diaphragm exhibits rapid rest and respose times. Neodymium ferrous magnet system ensures optimum sensitivity. Built with luxurious comfort and lasting durability audiophiles demand. Detachable impedance-matched cable with ultra-low capacitance. Impedance: 300 ohm. Frequency response: 12-40500Hz. Comes with adapter to 1/4" stereo jack plug.