Features: Mini and Invisible: Super mini size headphone, invisible and 4g lightweight design is suitable for working, driving, running, climbing and other sports. BT Connection: Wireless BT 4.1+ERD Technology ensures transmitting strong signal in high quality and high speed and offering high-fidelity stereo music. Hands-free with Mic: Hands-free call helps your avoid the danger when driving. With multi-point connection, you can switch between your business and personal phones. Simple Operation: Simple operation, easily control playing / pausing music, answering / rejecting / ending an incoming-call and redialing the last number. Duration Time: With built-in 55mAh Li-battery, it provides 3-4 hours of working time and the standby time can last to 30 hours.