A9 Pro Smart Colorful Touch Screen Noise Reduction Wireless Bluetooth Earphone Features: 1. Full-color smart touch screen, easy to operate 2. Active noise reduction + call noise reduction, clear calls without noise 3. Adopt Bluetooth 5.4 version, fast transmission speed and stable signal 4. 13mm driver unit, HiFi-level sound quality, immersive stereo surround sound effect 5. Ergonomic design, in-ear adapt to the ear canal, light and comfortable to wear Parameters: 1. Chip: Advanced noise reduction 2. Bluetooth version: 5.4 3. Transmission distance: 15m (barrier-free) 4. Working frequency: 2.402-2.480GHz 5. Charging time: 1H 6. Charging compartment battery type: 3.7V polymer battery 7. Charging compartment battery capacity: 500mAh 8. Headphone battery capacity: 30mAh 9. Charging input: DC 4.75-5.25V 600mAh 10. Weight: about 68.5g