Specifications:
Pocket Hearing aid
Max Sound Output: 129±4 dB
Max Sound Gain: 55dB ± 5dB
Harmonic Wave Distortion: ≤5%
Frequency Range: 450~3500 hz
Input Noise: ≤30 dB
Battery: 1 x AA battery (NOT included)
Working Voltage: dc1.5V
Working Current: ≤4mA
Color: As the picture shows
Item Size: 7.0 x 4.2 x 1.8cm
Package Size: 8.2 x 12.5 x 4cm
Net Weight: 28g

Package included:
1 x X-136 Hearing aid
2 x Earplug (different sizes)
1 x User manual

Note:
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.
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 plug, make sure no air leakage.
Keep the ear plug clean
Remove the battery if you don't use it for long time.