. BT version: v5.4. Chip: AC6973D4. 2. Supported protocols: Headset, Hands-free, A2DP, AVRCP. 3. Transmission distance: 10m. 4. Transmission frequency: 2.4GHz. 5. Speaker unit: 9mm. 6. Impedance: 32Ω ± 15%. 7. Frequency response: 20-20000Hz. 8. Sensitivity: 98dB ± 3dB. 9. Battery capacity: charging case 300mAh, headset 35mAh. 10. Charging case input: DC5V, Type-C. 11. Charging time: about 1.5 hours for charging case, about 1 hour for headset. 12. Talk / music time: 6 hours (80% volume). Total working time: 27 hours. 13. Mini donut design, with silicone protective case and lanyard. Breathing ambiance light effect. Serves as both an headset and a fashion accessory. 14. Supports leader-follower switching, voice assistant activation, songs switching, songs play / pause. 15. Headset automatically turns on when taken out from charging case, automatic pairing. Headset automatically turns off when inserted into charging case. 16. Battery display: supports for iP phones and some Android phones. 17. Sizes: 55 × 56 × 20mm. 18. Total weight: 32.2g. Single earbud weight: 3.5g.