QuietComfort wireless headphones II are engineered with world-class noise cancellation. And now they’re even better. You can adjust your level of noise cancelling between three levels to better fit your environment. You know the feeling. The kind you get when the rest of the world melts away and you’re transported to a place where it’s just you and your music. With Acoustic Noise Cancelling technology, you feel it at the flip of a switch. It continuously measures, compares and reacts to outside noise, then cancels it with the opposite signal. So however the music makes you feel, you can really feel it. With nothing in the way. Enjoy up to 20 hours of listening, enough time to pore through this entire playlist. And when it finally runs down, a quick 15-minute charge gives you another 2.5 hours. For that rare time when you do get caught without battery, use the included cable to plug in and keep the music playing.