F-138 Mini Device Volume Adjustable Sound Voice Amplifier Enhancement Hear Clear for the Elder Deaf Aids Care

About Whistle , you can do this 3 steps to remove it.

1. Choose a suitable earplug to make the product sealed in the ear canal 2. Low down the sound volume 3. When you put into battery , please be quick , to put the product into the ear

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. Keep the ear plug clean Remove the battery if you don't use it for long time.

Features:

Power tone F-138 In-Ear Hearing Aid is a quality hearing aid which can help you hear the sound clearly and loudly. The volume can be adjusted to 4 different levels.

Accurate and easy to use Volume can be adjusted with 4 levels. Help you hear the sound clearly and loudly, whether indoors or outdoors. Maximum loudness 130 ± 5dB. Sensitivity: >/= 50dB. Frequency range: 300Hz ~ 4000Hz. Total harmonic wave distortion :< /=5% Input noise :< /=30dB Voltage: 1.5V Current :< /= 4mA

Package Includes:

1 x F-138 In-Ear Hearing Aid 1 x LR44 1.5v Battery 3 x earplugs 1 x Manual