Features: Wireless BT 4.1 ensures transmitting strong signal in high quality and high speed, delivering high-fidelity stereo music. In-ear headset with ear-hook, brings you immersed music enjoyment and not easy to fall. Built-in microphone enables hands-free calls to set free your hands when doing sports. It also supports multi-point technology. Easily control playing / pausing, adjusting the volume, previous / next songs, answering / rejecting / ending calls. Ergonomic design guarantees wearing stable and comfortable when exercising, running, climbing and other outdoor sports.