Specifications1. Bluetooth chip and Bluetooth version: Realtek L8763 low power core V5.0+EDR2. Bluetooth protocol: HSP1.2, HFP1.6, A2DP1.3, AVRCP1.53. Rated voltage: 3.7V4. Rated power: 8mW5. Current (Rated current): 8ma6. Load description: 32Ω7. Headphone battery: single side 50mAH, plus protection board polymer battery8. Charging box battery: 450mAH, with protective plate polymer battery9. Charging power: Headphone 5V/1mA, charging box 5V/1mA10. Transmission distance: 10 meters11. Frequency: 2.4GHz-2.48GHz12. Listening to the song time: about 5 hours13. Talk time: about 5 hours14. Standby time: about 150 hours15.(1) Charging time (headphones): About 1 hour(2) Charging time (charging box): About 2 hours(3) Charging times (charging box): 3 times(4) Single earphone charging time (USB charging slot): Approx. 1.2 hours