【Sound Quality Switching Function】 L Mode: Best for quiet places like home or phone calls H Mode: Best for noisy places like amusement parks or train stations ■Product Features 【High-Performance Digital Sound Amplifier】 ・Uses high-grade medical-grade silicone ・Maximum acoustic gain of 45dB ・Suitable for both ears ・40 hours of continuous use 【Up to 40 Hours of Continuous Use】 ・High-performance sound amplifier that can be used all day long ・Easy charging, just plug into USB ・No battery replacement needed, easy to use ■How to Use 1. Turn the volume to the minimum 2. Turn the power ON 3. Put on the sound amplifier 4. After wearing, increase the volume 5. After use, remove the sound amplifier and charge it ※Since the sound amplifier is a special electronic product, a slight electrical hum may occur when starting up, but this is a normal phenomenon and does not affect the product's quality. 【Included Items】 Storage case Sound amplifier unit 3 types of earplugs (S, M, L) USB cable Small cleaning brush