A must-have for all digital photography enthusiasts: it can store many SD cards or other formats (see description), and 4 batteries size you want. An elastic band inside also allows to slip a USB key that seems to kick back perfectly (I'm not talking about USB key format "mini" I do not have and why I do so to opinion). The cards are protected against falling and dust. I did not realize test for moisture: I think this would cover water quickly enough for immersion but that it fears nothing when little rain. Also memory cards are often quite resistant.
I personally use this bag in my work computer, and acts as a first aid kit: a small RJ45 cable returns to it (1m) and SD cards containing software, and backup batteries for Customers with mouse stopped working while you perform your maintenance operations.
