AUX MODE
Press power button to power on, 'FM" is the default mode, then convert SOURCE button to AUX
mode, connect up the external audio, the unit will play music and you can press VOL- and VOL+
adjust to your desired volume
USB CHARGING
2 USB charging port, when 1 USB port used, the USB output is 5V/2A, when 2 USB port
used, the USB output is 5V/1A