Features:1.Brand new and high quality hearing aid sound amplifier 2.Super mini size and light weight, not easily to be seen 3.Adjust volume to the minimum before wearing Increase volume gradually to avoid sudden increase in sound 4.Convenient for watching movie, enjoying the drama, attending meeting, or having class, it could help you hear the sound clearly and loudly.Specification:1. Max sound output: 110±5dB 2. Sound gain: ≥30dB 3. Total harmonic wave distortion: ≤10% 4. Frequency range: 300-4000Hz 5. Input noise: ≤40dB 6. Voltage: DC1.5V 7. Current: ≤4mA 8. Color: As pictures