Power inputDC 5V Charging interfaceType-C Battery capacity 3.7V /40mAh (Earbuds) Battery capacity 3.7V /750mAh (Charging compartment) Call/Play timeabout 6 hours Charging timeabout 60 minutes Supporting agreementHSP/HFP/A2DP/AVRCP Sensitivity1013db@1k, 1mw Frequency range20-20000Hz Impedance32 Audio decodingQualcomm aptx/aac/sbc Sound 14.2MM dynamic unit, Perfect audio curve DesignHalf-in- ear wearing design, comfortable in wearing Bluetooth Qualcomm 5.2 chip, CVC call noise reduction technology Master-slave Two earbuds can be used independently