Z-127C TWS Charging Hearing Aid Sound Amplifier Auxiliary Listener 1. High-quality material, safe and non-toxic, suitable for long-term use. 2. Mini and lightweight, ergonomic design, invisible and comfortable to wear 3. Intelligent noise reduction, it can greatly reduce noise and provide high-definition sound quality. 4. The volume is adjustable, easily adjust the volume to meet your needs. 5. Suitable for the elderly and hearing impaired 6. Comes with different types of ear tips to suit different ear sizes. 7. Comes with a charging case to charge your device anytime, anywhere. (The charging case has no built-in battery and is powered by most USB devices) parameter: 1. Material: plastic 2. Sound output : 115dB 3. Sound gain: greater than or equal to 28dB 4. Frequency range: 300-3500MHz 5. Input noise: 32dB 6. Voltage: DC1.5V 7. Current: less than or equal to 2mA 8. Hearing aids (each): Built-in 25mAh rechargeable battery 9. Charging time: less than or equal to 6 hours 10. Working hours: less than or equal to 16 hours Packing list: 1 pair of hearing aids 1 x charging case 6 x earplugs 1 x small brush 1 x charging cable 1 x user manual (English)