Model LK138
Standard Features: 
√ Middle Output. 
√ Attractive design. 
√ Ultra-light Weight.
√ Less noise, fine fidelity and tone.
√ With ON/OFF switch.
√ With imported microphone and receiver. 
√ Tested according to International Standard IEC118-7. 
Specification:
 Max Sound Output: 125±5dB
 Sound Gain: ≥43dB
 Total Harmonic Wave Distortion: ≤8%
 Frequency Range: 400----6200Hz
 Input Noise: ≤28dB
 Voltage: 1.5V
 Current: 10.8mA
 Battery: A675 Zinc-Air/ AG13 Button Cell
 Estimated Battery Life: Over 100 hours (with A675 Zinc-Air)