AIN MK-X18S USB Car Single Wireless Bluetooth Earphone with Charging Box, Support HD Call & Siri & Automatic Pairing Features: 1. Bluetooth 5.0 chip, approaching zero delay, smooth operation without lag 2. 8mm sound unit, showing crisp and clean sound quality 3. One-key operation, support for high-definition calls, wake up voice assistant and other functions, easy to use 4. Wear a single earphone, you can pay attention to the sound of the surrounding environment, suitable for driving and safer 5. Remove the headset from the charging box, the headset will automatically pair and connect 6. Use with the charging box, long-lasting battery life 7. Comes with USB charging cable 8. Ergonomic design, comfortable to wear Product parameters: 1. Bluetooth version: V5.0 +BR+EDR+BLE 2. Channel system: mono 3. Working frequency: 2.402-2.480GHz 4. Support protocol: A2DPHFPAVCTPAVRCPAVDTPSPPSMP 5. Transmission distance: 10 meters 6. Transmission power: Class 2 7. Sensitivity: 105dB+-3dB 8. Response frequency: 20-20000Hz 9. Speaker unit: diameter 7mm, 16 ohm +- 15%, 92+-3dB, 1mW 10. Microphone: 4013, -42+-3dB 11. Charging input standard: contact, DC 4.75-5.25V1-40MA 12. Battery type: 3.7V lithium battery, 40mAh 13. Charging time: about 1.5 hours 14. Working time: about 3-4 hours 15. Standby time (shutdown): about 150 days 16. Indicator light: 1 x blue light, 1 x red light (xhc-03)