Color: Black, so that dirt tracks are not visible. To distinguish I have each white characters plus logo once dyed red and even blue with a permanent marker. Furthermore, Black is not so striking when worn (and compatible with any clothing that should be important to someone).
Size: my wife and I did this size fit for supplying the basics accurately (passport, wallet, cell phone, reading glasses, compact camera, tissues), without the bag would apply thick or would bulky. But everyone has secure his personal desire size - try it!
Material: the bags were not subjected to abrasive forces, but act, although they are light and soft, strong.
Belt: Length easily adjustable, belt-end can be powered by a plastic clip. At each time the bag I make the belt long, then draw him - this super handling. For security (against theft) can close the belt in the belt loops of trousers and move there.
Compartments: front compartment: Because I was afraid to tilt when you open the zipper (from bottom to top) is equal to the entire front compartment contents into the open air, I was sewing in my pocket the first line of the zipper (from bottom right to top right) with twine to and moved with hot glue gun trace over this section of the zipper. Thus, when opening captured the vacant position of the front compartment of not down, but up. All zippers are smooth and not damaged.
The body-facing side is covered with foam and mesh, so that there forms relatively little sweat and a high wearing comfort is given.
Price: by destination country Austria about 10 euros each. Inexpensive.
One star deduction due to the described and addressed by tinkering misconstruction.