F - 138 hearing aid

F - 138 hearing aid

Features:
100% brand new sound amplifier behind the ear
Super mini size and light weight, not easily to be seen
Adjust volume to the minimum before wearing
Choose an earplug of slightly bigger size to avoid whistler
Increase volume gradually to avoid sudden increase in sound
Color: as pictured
Technical Specifications:
Max Saturated Sound Pressure: 130dB+5dB
Sound gain: 50db
Harmonic Wave Distortion:5%
Frequency response Range: 300--- 4000 Hz
Input Noise: 30 dB
Power Voltage :1.5 V
Battery Type: AG13 button cell battery (included)