In the winter I volunteer to be a snowshoe guide for 4th graders. Easy trips, on the level, duration about 1.5 - 2 hours. What I needed was a small pack to hold visual aids: not just photographs, but also perhaps a beaver pelt and skull, or the lower leg of a deer. One of the other guides has this backpack and recommended it. For me, it's ideal: very secure, quickly swings round in front to be accessible, has two compartments so that I can keep my materials sorted out, and has just enough capacity to do the job. Much better than a conventional backpack (has to be taken off and put on the snow), or a fanny pack (too small). But it's far too small if you need to carry a lot of gear for more ambitious trips, or carry a DSLR camera and lenses.