Hearing aid, When you watch movie, enjoythe drama, attend meeting, or have classes, the product can help you to hear the sound clearly and loudly. While in forest, if you want to hear very slight sound, it will be a good choice.

Specification:
1.Max sound output:110+-5Db
2.Sound gain:about 30dB
3.Total harmonic wave distorting:about 10 ???
4.Frequency range:300-400Hz
5.Input noise: about 40dB
6.Voltage:d.c.1.5V
7.Current: about 4mA