Types:A Features: -There are five levels of volume control with beep prompts. -Equipped with portable charging case, 3-4 hours to full power of the case, can offer totally 36-90 hours of use. -The operation is simple, long press to turn on and short press to adjust the volume, making it convenient for the elderly to use. -High-definition sound quality enables barrier-free communication, and the full-scale gain is greater than 35dB. -The cochlear ergonomic design is comfortable to wear and can be used for a long time. .