There're external USB charging port and internal USB charging cable. So you need to put your Portable Charger into backpack and connect internal USB charging cable, then let your charging cable insert external USB charging port to connect your electronic device. Easy access and convenient to charge anywhere.
You have to buy a separate portable power station. You put the power station in the backpack and then plug in your phone on the external connection, put your phone in the mesh pocket, and you're good to walk around the airport while charging your phone! It's great!