Power inputDC 5VCharging interfaceType-CBattery capacity 3.7V /40mAh (Earbuds) Battery capacity 3.7V /750mAh (Charging compartment) Call/Play timeabout 6 hours Charging timeabout 60 minutesSupporting agreementHSP/HFP/A2DP/AVRCPSensitivity1013db@1k, 1mwFrequency range20-20000HzImpedance32Audio decodingQualcomm aptx/aac/sbcSound 14.2MM dynamic unit, Perfect audio curveDesignHalf-in- ear wearing design, comfortable in wearingBluetooth Qualcomm 5.2 chip, CVC call noise reduction technology Master-slave Two earbuds can be used independently