Large chassis for best sound quality. The PX7's 43mm drivers are the largest drivers used in one of the headphone models. They were developed by the same engineers responsible for the 800 Diamond Series speakers used at Abbey Road Studios. Adaptive noise cancelling that automatically responds to your environment to keep the outside world away from your music. You can do a lot of things in 30 hours. Enough time to fly from California to London and back, for example. All this is possible with a single battery charge without interruption. And if that's not enough, you'll get another 5 hours of play with just 15 minutes of quick charge. The PX7 follows your every move. When you lift an ear cup, the PX7 automatically pauses your music. Music playback will resume as soon as you lower the earpiece again. The PX5 and PX7 headphones use the same carbon fiber composite materials that are used in modern racing, providing the highest levels of strength and durability.