4. Here you can see the back of the bag with the roll bag installed. The roll bag attaches to the main bag with a quick and easy buckle system (roll bag can be mounted separately as well). Here you can also see the solar panel in the back of the bag. The solar panel is removable if you should ever want to take it out. There are two pockets on each side of the bag, two of which are expandable to give you even more storage.