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 plugged, make sure no air leakage.

Keep the ear plug clean.

Remove the battery if you don't use it for long time.

Specifications:

Product Name:Pocket Hearing aid

Max Sound Output: 129±4 dB

Max Sound Gain: 58dB ± 5dB

Harmonic Wave Distortion: f<1000Hz≤15%,f＞1000Hz≤10%

Frequency Range: 450~3500hz

Input Noise: ≤30 dB

Battery: 1 x AA battery (included)

Working Voltage: dc1.5V

Working Current: ≤4mA

Color: As the picture shows

Item Size: 6.1 x 4.1 x 1.6cm

Package Size: 18 x 9.8 x 3.8cm