Model LK148
Standard Features: 
√ Attractive smallest design.
√ Ultra-light weight. 
√ Less noise, fine fidelity and tone. 
√ With ON/OFF switch.
√ With volume adjustment switch. 
Specification:
 Max Sound Output: 125±5dB
 Sound Gain: ≥40dB
 Total Harmonic Wave Distortion: ≤5%
 Frequency Range: 250---3800Hz
 Input Noise: ≤28dB
 Voltage: 1.5V
 Current: 8mA
 Battery: LR41 Zinc-Air/ AG13 Button Cell  
 Estimated Battery Life: Over 144 hours