1. Bluetooth version: 5.0+DER 2. Bluetooth protocol: HFP/HSP/A2DP/AVRCP 3. Headphone battery: 40 mAh 4. Storage box battery: 5200 mAh 5. Storage box power output: 5V/2A 6. Small size, easy to carry 7. The earphone is connected when taken out, and disconnected when put back 8. Ergonomic design, comfortable to wear 9. Size: 12.6x8.6x3.6cm