M520 Ear-mounted Stereo Bone Conduction Sports Bluetooth Earphone 1. Bluetooth version: 5.2+EDR 2. Transmission distance: about 10 meters 3. Talk time: about 48 hours 4. Listening time: about 26 hours 5. Battery capacity: 150mAh 6. Accessories: earphone x1, charging cable x1, manual x1 7. Wireless frequency: 2.4GHZ 8. Support protocol: A2DP1.3HFP1.6HSP1.2AVRCP1.6D11.3 9. Charging voltagecurrent: 5V1A 10. Power: 5W 11. Charging time: about 2 hours 12. Speakerimpedance: 8mm32 ohm 13. Microphone sensitivity: -42dB 14. Support functions: Chinese and English switchingcaller IDvoice assistant calllos battery displaytwo earphones of any color can be combined into TWS binaural function 15. Size: about 7.7x4x0.9 cm 16. Weight: about 36 grams Features: 1. Biological diaphragm, the sound quality is transparent and powerful, the audio that restores the sound quality is bright, the middle frequency is full, and the low frequency is thick and flexible 2. IPX5 waterproof design, effectively prevent rain and sweat, easy to clean material 3. Inward adjustment can clamp the ears, the earphones will not fall when bending down, and outward adjustment can facilitate the earphones to hang on the ears 4. Reduce signal interference, disconnection, no delay in the call, and clearer 5. Noise reduction ear protection, comfortable to wear 6. Using Bluetooth 5.2 chip, the connection signal is stable, effectively reducing the lag