1. This hearing aid is specially designed for the elderly or people with hearing problems, suitable for those people or patients with hearing loss. 2. Double noise reduction, low power consumption, high fidelity, high-quality chip. 3. Small in size and light in weight, it helps you get rid of the shackles of earphone wires, and is convenient for watching movies and enjoying dramas, etc. 4. Ergonomic earplug design, even if you wear it for a long time, you will not feel pain. 5. Specifications: - Power supply: rechargeable - Rated operating current: less than 1.4mA - Frequency response: 300-5000 - High frequency average: less than 106db - Sound gain: 28db - Total harmonic distortion: less than or equal to 7+3% - Equivalent input noise: less than or equal to 29db+3db - Sound output: 128db - Voltage: DC3.7V