Max Sound Output:	130±5 dB
Max Sound Gain:	≥50 dB
Harmonic Wave Distortion:	≤5‰
Frequency Range:	300~4000 hz
Input Noise:	≤30 dB
Battery:	Rechargeable and Replaceable Battery
Max Working Hours with Standard Battery:	50 h
Working Voltage:	D.C. 3.7V
Working Current:	≤4 mA
Measurement:	5.7×2.6×1.8 cm
Net Weight:	27 g (with Battery)
Special Function Key:	N-H Key