1. For running: It is upgraded firmly, even in running, fitness and other sports, it can be worn stably. 2. Sensitiveness: It has 6D double coil with Double Bass, metal cavity 1080Db, high sensitivity, high fidelity. 3. High definition call: It has voice fiber, deep noise reduction, put the external noise, voice call, clear visible, let the noise away from your life, return to the pure . 4. Ergonomic design: This product adopts ergonomic design and is very comfortable to wear. 5. Portability: This product is small in size and light in weight, very convenient to carry around. Specifications: Transmission range: 10 meters Function: battery display, call function, NFC function, voice control, music support, multi-point connection Wireless protocol: 5.2 Channel: Mono How to use: Earplugs Whether single and double ears: unilateral hands-free Material: ABS colour: Black Package Contents: 3 x Headset Only the above package content, other products are not included. Note: Light reflection and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.