I7 TWS Bluetooth Wireless Mini Headphones Stereo With Mic Ea

1. controller: 15mm 2. impedance: 32 ohm 3. bluetooth version: bluetooth 5.0 + edr 4. bluetooth band: 2.4 ghz 5. power level: level ii 6. output power: 30 mw 7. bluetooth distance: 10 m barrier 8. frequency response range: 20-20000hz 9. working voltage range: 3.0v-4.2v 10. microphone sensitivity: -42db 11. high quality stereo audio transmission and remote control protocol with a2dp / avrcp 12. powerful noise breaking circuit (active noise reduction) 13. switch between chinese and english (cannot connect to bluetooth status, please press this switch twice to listen to the tone switch correctly) 14. the talk time is 1.5-2 hours. 15. music time is about 1.5-2 hours 16. waiting time is about 100 hours