1. Maximum sound output: 126+/-3dB
2. Sound gain: greater than or equal to 35dB+/-5dB
3. Total harmonic distortion: less than or equal to 3%
4. Frequency range: F1 less than or equal to 200Hz, F2 greater than or equal to 4500Hz
5. Input noise: less than or equal to 15dB+/-3dB
6. Voltage: DC 3.7V
7. Current: less than or equal to 1mA
8. Fully charged in about 2 hours, working for about 40 hours
9. Charging through the magnetic charging box, working time exceeds 100 hours
10. Digital DSP 16-channel professional system
11. The ear canal design is almost invisible and comfortable to wear
12. The charging status of the digital charging box is clearer