1.Note : If the size of the earbud tips does not match the size of your ear canals or the headset is not worn properly in your ears, you may not obtain the correct sound qualities or call performance. Change the earbud tips to ones that fit more snugly in your ear 2. Signature Sound: Nothing beats incredibly clear music and calls from 11mm dynamic drivers powered by Signature Sound. 3.True Adaptive Noise Cancelling with Smart Ambient: True Adaptive Noise Cancelling automatically adjusts to your surroundings, eliminating distractions for better sound wherever you are. Or use Smart Ambient when you need to focus on your environment, all without removing your earbuds. 4.35 (7+28) hours of playback with wireless charging: Never miss a moment with 35 hours of Qi-compatible battery life (including 7 hours in the earbuds + 28 hours in the case). Need a boost. Just 15 minutes of Speed Charge gives you another four hours of playtime—fast.