It can use 5V 3A, as router will use <10W and usb/micro sd <5W. I was supposing it works like the Flint, but perhaps I am wrong. Home routers usually choose 12V to provide >=5W to power hungry usb devices while maintaining current <3A (5V*3A=15W while 12V*3A=36W). A 15W can power a usb drive, but probably not an old 2.5 mechanical drive or a power intensive ssd.