Bluetooth 4.0: With the latest Bluetooth 4.0 this Bluetooth headphones offer enhanced sound transmission, faster pairing, more stable wireless connection and wider compatibility with Bluetooth enabled cell phones, tablets, computers, smart watches. 2.Call Vibration &Noise-Cancelling Mic: Bluetooth headset will vibrate when a call comes in so that you won't miss any calls even you are doing exercise or in noisy place. The built-in noise-cancelling microphone can reduce background noises so as to provide crystal-clear sound for hands-free calls. 3.Playtime: Its powerful rechargeable battery provides up to 10 hours of continuous music or phone conversation with a single full charge. 4.Auto Retractable Earbuds:You could pull each ear bud up to the maximum length when you use it. Pull it again and it shrinks in when you don't use it, Very convenient especially when running.We adopt high quality wire 5.Lightweight Neckband : Design by ergonomics will let it fit your ear firmly, the lightweight material provide safe wearing without pain and the ears wont feel discomfort after you wear long time.