These comfortable and lightweight in-ear headphones feature Denon's advanced active noise canceling technology reducing unwanted ambient noise by up to 99%. Large 13.5mm drivers provide wide dynamic range throughout the entire audible spectrum. These drivers are encased in Denon's hybrid material driver housings contributing to exceptional sonic neutrality. Powered by a single AAA battery, widely available on the go, the AH-NC600 headphones provide up to 60 continuous hours of noise reduction. The headphones can also be used without the noise canceling function activated. Denon's Acoustic Optimizer technology provides exceptional balance that is free from enclosure-induced coloration. The AH-NC600 are the first Denon headphones to feature the innovative Compressed Audio Restorer function, which restores very high frequency harmonics that are lost in the audio compression process. For optimum fit and comfort, the AH-NC600 headphones are supplied with 3 sizes of silicon ear pads (S/M/L) as well as a separate pair of soft foam ear pads. The deluxe carrying case can be used as a stand for your portable A/V player.