Description Bluetooth version 5.3 (AD6973D4) Supported protocols: HSP, HFP, A2DP, AVRCP Channel system: Stereo Battery capacity of earbuds: 35mAh*2(without protection board but IC) Battery capacity of charging case: 3.7V/300mAh(with protective plate)   Diameter of horn: 13mm Charging time 1h  Talk time 7h Play time: 6h (Used with charging case under 80% volume: 20h)   Standby time: 200h Sensitivity 93±3dB   Impedance: 32Ω Input standard voltage: DC 5V Frequency response range: 2.402GHz~2.480GHz Maximum transmission distance: 10m Voice prompt: supported  Multi-point connection: unsupported  Wearing method: semi-in-ear User manual: Chinese and English Port: Type-C   Waterproof rage: IPX6 Included accessories: USB charging cable, user manual