Specification :

Max Sound Output: 130 ± 5 dB
Max Sound Gain: e50 dB
Harmonic Wave Distortion: d5‰
Frequency Range: 300~ 4000 hz
Input Noise: d30 dB
Battery: AG13 Button battery
Max Working Hours with Standard Battery: 70 h
Working Voltage: D.C. 1.5V
Working Current: d4 mA
Measurement: 5.3× 4.4× 1.0 cm
Net Weight: 9 g ( without Battery)
Special Function Key: None