Features:

Bluetooth Version: V4.0 
Product: HIFI Bluetooth Headset
Product Size: Φ42mm (Driver)
Packing Size: 265*215*85mm
Material: ABS+PC
Weight: N/W 253g G/W 856g
Colour: Black, Red,Blue, Orange
Rated Power: 20mW (Max Power 30mW)
Rated Impedance: 32Ω±10% (S/N Rate 80dB)
Sensitivity: 105±3dB (at 1kHz)
Distortion Degree: <2% 94dB (20μpa) 
Channel Balance: <2dB (at 1kHz)
Frequency Response: 20Hz~20kHz
Transmission Standdard: CLASS 2 (≤10M)
Standby Time: >150 hrs (Battery saturation)
Working Time: >7 hours (Volume 50%)
Charging Time: 2~3 hrs
Charging Voltage: USB 5V (DC 5V 500mA socket)
Built-in Battery: Polymer lithium ion 3.7V 320mA
Channels: 79 channels of 1Mhz BW

Package included:
1 X Bluetooth Headset Earphone
1 X Manual
1 X Certificate
1 X Warranty Card