Powerful, Fasional. with excellent function.Max Sound Output:  130±5 dB
Max Sound Gain:  ≥55 dB
Harmonic Wave Distortion:  ≤5‰
Frequency Range:  300~4500 hz
Input Noise:  ≤30 dB
Battery:  Rechargeable Li Battery
Max Working Hours with Standard Battery:  80 h
Working Voltage:  D.C 1.5V                                                 Working Current:≤1.5mA                                                  Net Weight:66g(without Battery)                                         Rechargeable                                                                       Bluetooth(Optional)