DASHUHUWAI FM Radio Digital Rechargeable Sound amplifier in ear hearing aid E-8 E-8 is a digital hearing aid with FM radio function, it built in high quality lithium battery, the capacity is 85mAh it can work for 50 hours after fully charged, 300Hz~10KHz low power consumption and long life, Sound gain of 57dB ,set a press button for adjusting the frequency, include low, middle, high and wide total 4 frequency for your choice. Strict quality control, test by the hearing aid test machine of Fonix 6500-C,Fonix 7000 and CR6128 Adjustable low/middle/high/wide 4 frequency, 300Hz~10kHz low power consumption and long life. Lithium battery, the capacity is 85mAh, it can work for 50 hours after fully charge