Features1Ergonomic Design: The product is made of medical grade silicone material, which is easy to enter the ear and not easy to fall off. 2Sound Quality: The product uses imported chips, with clear sound quality and stable transmission. It can prevent whistling and reduce noise. 3Invisible Design: The product is small, light and easy to use; It adopts skin color and invisible design, which is not obvious from the appearance. 4Applicable Crowd: The amplifier is equipped with earplugs of different sizes, which is suitable for all people with needs. You can choose different sizes according to your own situation. 5Hearing Recovery: The sound amplifier can help people in need recover their hearing, rediscover the fun of gathering with friends and family, feel more confident in work, and watch movies, music and TV programs.SpecificationItem Type: Sound amplifierMaterial: ABS siliconeEarphone Battery Type: Lithium battery (shipped with built in battery)Battery Type of Charging Bin: Lithium battery (shipped with built in battery)Headphone Battery Capacity: 35mahCharging Compartment Battery: 500mAhFrequency Range: 450 to 4500HzNoise: 32dBWeight:204.00g/7.19ozPackage List1 xSoundAmplifier5 x Earmuffs1 x Brush1 x Instruction1 x Charging Line1 x Charging Chamber