About this item 【High-fidelity Stereo Sound Quality】- built-in high sensitivity microphone and noise canceling technology(not active noise cancellation), ensure crystal high quality sound no mater you are calling or listening to music. 【Outstanding Battery Performance】- The portable designed headphone built with large capacity battery, which provides up to 16 hours of continuous music time and 300 hours of standby with a single charge. 【Advanced Bluetooth 4.1+CVC 6.0】- latest Bluetooth 4.1chip provides fast, stable and low-power connection. These headphones are compatible with most smart phones, iPhone, Android devices and other Bluetooth Enabled Devices. 【Neckband Design】- Around-the-Neck wearing design with perfect Body-Contoured fit. Made of environmental ABS+PC material, light and soft to wear comfortably, perfect for long time wearing no matter in outdoor activities or in office. 【Foldable and Retractable Design】- Foldable design enables you to take it anywhere in your pocket or in your bag. Retractable Earbuds- a unique design for cable management, no more tangled wire obsession.