Bluedio HT Wireless Bluetooth 4.1 Stereo Headphones Earphone built-in Mic handsfree for calls and music Headset Original Box Specification: General Brand Bluedio Model H Color Black Wearing type Headband Function Noise Cancelling, Microphone, Voice control, Answering phone, Song switching, Bluetooth, Multi connection function Specification Connectivity Wireless Connecting interface USB Application Mobile Phone Plug interface Full-sized Driver unit 57mm Frequency response 20~20KHz Impedance 16ohms Sensitivity 110 dB Power supply USB port DC 5V Working time Talk time: 45 hours; Music playing time: 40 hours Standby time Up to 1625 hours Charging time About 2 hours Extended Function Bluetooth Yes Bluetooth version V4.1 Bluetooth distance W/O obstacles 10m Bluetooth band 2.4GHz-2.48GHz Bluetooth protocol A2DP, AVRCP, HSP, HFP Dimension and Weight Product weight 0.200 kg