Mini Apparecchi Acustici Digitali Ricaricabili Invisibili In Ear Suono Amplificatore Vocale!
Input Noise:<=28dB. Max sound out put:111+/- 5dB. Sound gain:>= 30dB+/- 5dB. 1 x USB charging cable. The recharging box with power capacity LED display. Full charing in 2~3 hours, working more than 30 hours.