In-Ear Smart Wireless Headset Bluetooth Stereo Earphones

Distance:< =10M
Version: V4.2
Charging Voltage: DC5V
Working Voltage: DC3.7V-42V
Battery Capacity: 55mAh
Frequency Range: 20Hz-20KHz
Speaker Impedance: 32ohm+/-10%
Loud Speaker Size: diameter 8mm Rated Power: 2mW
Sensitivity:102+/-3dB
Buit-in Microphone