Initially, it has plenty of space and many pockets with and without zippers. It comes with a "folder" for masks, with two compartments, one for new masks and one for used ones. Also, in one pocket for water bottles, it has a USB A male to USB A female cable and a corresponding opening so you can charge with an internal power bank without cables sticking out. In the tablet compartment, I have placed a 13.3" laptop and it fits perfectly. The front pockets are very large and comfortably fit thin books as well. In the main compartment, there are also 2 internal slots for water bottles. Between the large pockets, there are openings to pass cables from one to the other. One of the external zippers is for expanding the dimensions of the bag. Notably, due to its square base, it stands upright without support. The handle is sturdy and the clip in front of the chest is removable and can be stored. Finally, it has rubber feet at the bottom, to prevent direct wear and tear. It is very convenient on the back and probably fits more than what you can carry on your back.