A good quality backpack. The description on amazon lack information, but they can be easily found at deuter website.
For example, this backpack has an advanced structure, both to hold the backpack in position as to help the transpiration. It has frontal opening, which helps to quickly reach the middle of the backpack, without having to empty it to find something.
I`m also a owner of a Doite Lemaire (chilen brand), and I cannot compare both backpacks.
I do recommend to whoever is looking for a medium size backpack.