features of BT 4.2 Technology, built-in high-grade microphone speaker, hands-free calling function and lightweight design, the headphone is convenient for you to listen music and answer calls. A great companion for your daily life, office time, driving or travel. Features: BT Connection: BT 4.2 ensures strong signal and wireless connection range is 10 meters (no obstacle). Hands-free with Mic: High-quality Microphone grasps the detail of voice, ideal for in-car calling or working use. Long Battery Life: Built-in rechargeable 75mAh Lithium battery lasts up to 4 hours of music time on one full charge. Multi-point Connection: Can simultaneously connect two smart phones, switching between your business and personal phones. Easy Operation: Easily control volume+/-, playing / pausing, answering / rejecting / ending a call and redialing the last number. Antiradiation: Radiation shielding rate is up to 90%, no harm to human body.