2)Sound gain: ≥30dB,Adjust volume as your wishes;
3)Total Harmonic Wave Distortion: ≤10%
4)Frequency range: 300-4000Hz
5)Input noise: ≤40dB
6)Voltage: DC 1.5V
7)Current: ≤4mA
8)Adjust to either ear,Weight less than 10 grams;
9) Accurate and easy to use;
10)Help you hear the sound clearly and loudly, whether indoors or outdoors
4)Frequency range: 300-4000Hz
5)Input noise: ≤40dB
6)Voltage: DC 1.5V
7)Current: ≤4mA
8)Adjust to either ear,Weight less than 10 grams;
9) Accurate and easy to use;
10)Help you hear the sound clearly and loudly, whether indoors or outdoors