Bluetooth Digital 16 Channel Hearing Aid-Provide OEM & ODM 1. DSP chip, sounds great nice fit. You can be able to hear very clearly, to hear people who talk very softly. 2.External microphone, decrease whistling feedback. 3.Hard shell, drop-proof material, durable for longer use life. 4.400mAh Rechargeable case battery. 45mAh for one hearing aid battery, can use for over 40 Hours. 5.Smart blue tooth, no delay, music streaming support, hand-free phone call.