Advanced BT Technology: True wireless (TWS) BT technology ensures transmitting strong signal in high-quality & high speed and offering high-fidelity stereo music. TWS BT Design: Wireless dual ear stereo design, left and right ear channel separation. You can use the Left and Right ear earphone solely (single track mode), or use in pairs (stereo mode). HD Microphone: High-sensitivity microphone reduces ambient noises and grasps the detail of voice, ideal for in-car calling or working use. Useful Accessories: Included portable silicone lanyard and earphone case protects your earphone against bumps, drops and shock, very useful. Charging Box: The 450mAh charging box can charge for the earphones and can be used as a perfect storage case for them, protecting them from damages.