I did this usb hub to charge things in the back of my camper from a 12 volt battery, and also to have a monitor to see how many volt the battery has, so that I can know if it`s empty or full. I used an old harddisk case for the box, since its stronger and also has a port that I could already use. but in case you don`t have a case that fits, then i added also a printable caseThe included parts that are: XL4015 step-down converter, to convert from 12 to 5 volt using a potentiometer rocker on/off switch and a "mini panel voltage meter" connected directly to the battery (via the switch) the usbs are scavenged from an old tft screen but you can use regular usb ports connected with each other.