The stated volume of 3 liters:
This is a joke.
In the small, applied to the body bag fits a folded bike map, approximately 15x10x1 cm, then the end.
In the "large" means bag fits a durschnittlicher wallet, a cell phone with pocket, but a bunch of keys, then it gets really tight. If you still want to take a plug for rear light, the third bag is already full. For a GPS in cigarette size is no more space.
In the pocket watch with goodwill VII. 1.5 liters.
I recently got my (lack of space and the given water resistance) A 3-liter Ortlieb since fits loosely, really loose, twice pure and has more practical features, is just too expensive.
2 stars, because the processing for this price is really impeccable. Three deduction for the specified volume definitely wrong.
