Wireless bluetooth headset $ 6.78 Bluetooth chip and Bluetooth version: 4.1 Bluetooth protocol: A2DP AVRCP HFP HSP Battery: 3.7V 60mAh Charging power: 5V/80mAh Sensitivity: 103db +/- 3dB Impedance: 32Mw Transmission distance: 10m without barrier Frequency: 2.4GHZ Talk time: about 4 hours Listening time: about 5 hours Standby time: about 160 hours