Elderly Hearing Aids Invisible Sound Amplifier Noise Reduction Collector With Digital Display Charging Compartment 1. Rated voltage: 3.7V 2. Charging interface: Type-C 3. Battery capacity: hearing aid - 30 mAh, charging case - 300 mAh 4. MAX saturation sound pressure level: less than 118db±3db 5. High frequency mean: 103db±4db 6. Full tone gain: 30±5db 7. Frequency response range: not less than 350hz - 5000hz 8. THD (total harmonic distortion): less than 10% 9. Equivalent input noise level: less than 30db 10. Rated power supply current consumption: less than 3mA 11. Weight: hearing aid about 2.4g 12. Size: hearing aid about 2.5 x 1.5 x 1.2cm Features: 1. Intelligent noise reduction chip, filter noise significantly, sound is purer and more transparent, sound is not distorted 2. Silicone earplugs, soft and fit the ears, safe and comfortable, firmly worn, no falling off, no pain after long-term wearing 3. Invisible and pain-free, ergonomic design, comfortable to wear all day, small and light without burden 4. Physical buttons, simple operation, easy to adjust the volume, anti-fall and durable, more assured for the elderly to use 5. The hearing aid is equipped with a delayed start function to prevent howling and protect the ears, and comes with a digital display charging box for long-lasting battery life