... ,SD card 3.Battery:build-in recharg 728UDFM Professional portable wireless pa amplifierSpecifications:Voltage:AC 220V/110V ... Mic, Audio(USB,SD Card), FM radio. Frequency Range: 175MHz-276MHz(Wireless Mic) Sensitivity:10dBS/N:>60dBOscillating: ... QuartzWireless Effective Range:35M Application:Teaching, assembly, Conference, Church, Parade, ...