Portable Mini Hearing Aid Sound Amplifier

Specifications:

Max Sound Output: 130±5 dB
Max Sound Gain: 55±5 dB 
Harmonic Wave Distortion:?5?(500Hz)
Frequency Range: 300-4000 Hz
Input Noise:?30 dB
Battery: AG13 Button batteries (included 1pcs)
Working Voltage: dc1.5V           
Working Current:?4mA       
Color: As the picture shows
Item Size: 6.75 x 4.35 x 1.9cm            
Package Size: 10 x 8 x 3.5cm 
Net Weight: 7.5g

Package included:

1 x F-138 Hearing aid 
3 x Earplug (different sizes)
1 x User manual
1 x Box ( optional )

Note:

Adjust volume to the minimum before wearing.
2Choose an earplug of slightly bigger size to avoid whistler.
Increase volume gradually to avoid sudden increase in sound.
If you hear a howling, check the ear (silica gel) is appropriate and whether the size of plug is tight, the appropriate choice of earplugs and plugged, make sure no air leakage. 
Keep the ear plug clean
Remove the battery if you don't use it for long time.

WARRANTY

We'll refund your money if the item hasn't been delivered within 40 days after purchase. You have 2 weeks to request a refund — until day 60.
Product doesn't match the description? Contact us within 30 days after you receive it!
In case of cancellation, money will be refunded to your account within 3 days.