New.
Wearing a hearing aid means rediscovering the pleasure of gathering with friends and family, feeling more confident at work, and enjoying movies, music and TV programs.
Specification
1.Max sound output:110±5dB
2.Sound gain:>30dB
3.Total harmonic wave distortion: <10%
4.Frequency range:300Hz-4000Hz
5.Input noise: <40dB
6. Voltage: D.C. 1.5V 7.Current:<4mA