With advanced apt-X sound tech and Bluetooth 4.1, the headphones offers high-fidelity stereo sound and music for perfect listening experience Stylish Lightweight and Sweatproof perfect for running, biking or gym. Can be used as sports earphones, but not ideal for strenuous sports Bluetooth V4.1 EDR audio decoding technology, easier and faster pairing with smartphones, tablets, and other Bluetooth enabled music devices in seconds. Work with most Bluetooth-enabled devices, and can connect automatically with a device paired previously. Built-in HD Microphone with CVC6.0 noise reducing technology diminishes outside noises, makes you enjoy clear and natural sound. Bluetooth Headset Wireless Headphones Stereo Noise Reducing Description Specifications: Verson:Bluetooth V4.1 Battery: Rechargeable lithium-polymer battery Bluetooth Profile: A2DP/AVRCP/HSP/HFP/APT-X Call Time: about 5 hours Play time: about 6 hours Standby time: about 100 hours Charging time: about 2 hours