Superior Sound Quality: Tuned driver, CSR chip delivers HD stereo and superb bass sound. Bluetooth 4.1 and CVC6.0 noise cancelling technology with built-in mic for clear and stable phone calls. IPX7 Waterproof: Interior Nano coating effectively protects sport headphones from sweat and ensures a guaranteed life span, Great for Running, Jogging, Hiking, Biking, Gym, etc. 8 Hour Battery Life: Built-in lithium polymer battery. Only 2 hours’ charge gives up to 8 hours of audio; headphones battery capacity is displayed on your iPhone.