【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 need to replace batteries, easy to use ■How to Use 1. Minimize the volume 2. Turn the power ON 3. Wear 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 noise may occur during startup, but this is a normal phenomenon and does not affect the product quality. 【Included Items】 Storage case Sound amplifier body Earplugs (3 sizes: S, M, L) USB cable Small cleaning brush