... microphone 1pc 2.USB charging cable 1pc 3.F card transfer to SD card cover 1 PC Power supply3.7V(3.7V 500mAH ... earphone into the socket and listen music stored in MMC/SD card.USB input port is responsible for battery chargingUSBport, USB 1 ... , 30 dB at 1 kHz S.P.LImpedance, 32ohm +/- 10%Driver Unit, 40mmOutput power,10mWFM frequency Response,87.5MHz-108MHz