Hearing Aid SC 39

max sound output:120+3dB. Sound gain 23+5b, total harmonic wave distortion<10%.frequency range:300-3500HZ. Rate power supply for current consumption:6mA charging case working current:< 70mA.charging case working voltage:3.7v.hearing aid charging current <30mA hearing aid charing voltage:4.2V charging time of two. hearing aids with charging base:3-4 times