Equipped with Denon's innovative Dual Noise Cancelling system, the AH-NC800 headphones provide the optimum combination of quietness and audio fidelity. The AH-NC800 employs a Hybrid Aluminum Housing Material Housing to reduce ear cup resonance maximizing fidelity. It features not one, but two noise cancellation detection microphones. One microphone listens to ambient noise around the earpiece, while the other is internally mounted within the ear cup of the headphone to detect unwanted vibration and resonance. Together they provide superb noise isolation along with outstanding audio quality. For optimum comfort, the AH-NC800's feature 3D-contoured soft protein leather covers over super-soft compliant foam pads, together providing maximum acoustic isolation along with supreme comfort allowing for extended listening sessions without fatigue. The headphones are supplied with two different detachable Oxygen Free Copper cables, including a shorter (.7m) cable for connection to a portable audio player, and a longer (1.5m) cable for connection to a PC, airline jack or convention audio system. Both feature gold plated 3.5mm plugs. The headphones can be worn without the cable being connected, and can be used with or without the noise cancelling function activated. The AH-NC800 is also equipped with Denon's exclusive Compressed Audio Restorer circuitry, which provides re-construction of the full audio spectrum of compressed music formats. The anatomically correct light weight headband features 11 comfort adjustment steps. The AH-NC800 sets performance audio standards in noise cancelling headphones.