1. Double noise reduction, no need to adjust 2. Charge for 2 hours, battery life is 30 hours 3. Type: In-Ear 4. Power supply: rechargeable 5. Working voltage: 3.7V 6. Rated operating current: less than or equal to 1.4mA 7. Frequency response: should not be narrower than 300-5000 8. Maximum saturated sound output: less than or equal to 128+/-3 decibels 9. High frequency average: 106dB +/- 4dB 10. Gain: 28db+/-5db 11. Total harmonic distortion: less than or equal to 7%+3% 12. Equivalent input noise: less than or equal to 29+3db 13. Dimensions: diameter 42 x 31mm 14. Net weight: 4.3g
