You feel it the minute you put them on. The soft, plush cushions seal you in. Then you flip the switch and whooshthe world fades. The music starts, and its love at first listen. Thats the po headphones, now with a best-in-class combination of noise cancelling performance and premium comfort, plus proprietary acoustic technology for deep, clear audio. Bose QuietComfort® 45 headphoneswi balance of quiet, comfort and sound youll enjoy all day long. It all starts with our Acoustic Noise Cancellingtechnology, the result of more than 50 years of research. We use tiny microphones measure, compare and react to outside noise. That noise is then cancelled with an opposite signal, resulting in fewer distractionsand more of your music. Use the button on the left earcup to choose cancelling or Aware Mode to let in some of your surroundings. QuietComfort® 45 headphones give you more play time than their predecessor, with 24 hours* on a single charge. Enough to keep the quiet even the long