Reduce outside noise and enjoy your music more! Maxell's HP/NC-II uses microphones in the headphones to detect ambient noise that is interfering with your music. Information from the microphone is fed to the audio enhancer pack where it is analyzed and a precise active noise cancellation wave is generated. When this "anti-noise" wave meets the unwanted noise, the noise is reduced up to 95% so your music comes through loud and clear. With 16Db of noise cancellation, the NCIII has a full range (20 to 22,000hz) of frequency response with Neodymium magnets in a 40mm driver design. In addition to its high-quality stereo sound and superior noise cancellation technology, the Maxell HP/NC-II offers a collapsible design, a 6foot cord, travel pouch, dual prong airline adapter. The NCII is a lightweight closed ear design with longer battery life than most models on the market today, up to 50 hours of battery life. All important benefits to users who travel. Use Maxell's Noise cancellation headphones to enjoy your favorite music, or to simply block out unwanted noise. Road noise and airline noise can cause fatigue, and using noise cancellation headphones can help to reduce this fatigue. You arrive at your destination more energetic as a result. Or use noise cancellation headphones at home or in the office to block out ambient noise to help you concentrate and work more efficiently.The HP/NC-II also will provide sound without battery power, an important consideration for travel and to choose Maxell when purchasing a noise cancellation headphone.The HP/NC-II comes with a 90 day warranty for parts and labor.