High-performance hearing amplifier which can be easily operated by hanging behind the ear and is universal for both left and right ears, recommended for people with moderate hearing impairment. Volume is adjusted by rotating button; compact rechargeable battery is built-in, which can be recharged by USB. Digital signal processing can intelligently reduce noise, make the sound more real and more comfortable to listen. TPE medical silicone ear hook, long-term wearing will not cause skin hurt; One piece design, so that earplugs into the ear canal, wear more complimentary. Before using, first turn to the lowest volume, use the adjusting stick to adjust sound gradually until you feel comfortable. Generally, you will get used to it after 2-3 weeks. If not used, please Power off.