FunctionsQuietComfort wireless headphones II are engineered with world-class noise cancellation, And now they’re even better, With the Google Assistant built-in, you can play music, receive texts, and get answers without glancing at your phone, 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.