... welcome OEM service speaker metal usb speakersParameter:1, Output power: the RMS 2.4 W * 2 = 10 THD (F = 1KHz),2 ... + 5V battery parameters (machine)6, Nominal voltage: 3.7 V7, The rated capacity: 500mAh8, Battery limit voltage: 4.2 V9, Execution ... , Support SD card + TF phone card + USB interface, play the music memory CARDS7, Support the sound input interface 350 MM8, Support 3.5 ...