Description Product Description: “Bluetooth version and chip: 5.3, Jieli AD6973D4 Supported protocols: HSP, HFP, A2DP, AVRCP Talk time: 7H Play time: 6H Charging time: 1H Battery capacity of charging case: 300mAh Best call distance: <1M Maximum transmission distance: 10m Voice prompt: supported Sensitivity: 100.1dB Horn diameter: 10mm Impedance: 32Ω Frequency response range: 20H-20KH Multipoint connection: unsupported User manual: Chinese and English Included accessories: USB charging cable, user manual, earplugs of different size”