The history of military uniforms and accoutrements has seen a lot of design variation - for instance the humble cartridge box. By the time paper cartridges had come into use in the 18th century, there were any number of ways in which a soldier could carry them into battle. Some used bags slung over their shoulders, some used wooden blocks in leather cases in a similar position, and some - the Jägers and light infantry - were just as likely to have their ammunition in a wooden block/leather case strapped to their waists and worn in the front.
This may have been the inspiration for the Lowepro Streetline waist pack, though it is likely that it came from many of the same style that the company has made over a period of time. Now we are in the mirror-less era, the waist pack is coming into its own.
The reason for the Jägers' adoption of the design was the fact that they had to be agile and fast, prowling around the edges of a battlefield. Big cartridge pouches flapping on their flanks as they ran would have been murder. The designers of waist packs for photographic use might have considered this weight a problem as well - they made some pretty big boxes for the early DSLRs. The idea was there but the bulk of the load defeated the purpose.
Enter - as we said - the mirrorless camera and its lenses. Smaller, lighter, slimmer. Just the load for the new waist pack. And the lessons learned from the old ones re. the support system needed have now resulted in the new Streetline.
This pack has all the support you need in the belt plus a broad pad that spreads the load - and a non-slip surface to further secure it. Note that the pad has a channel behind it to allow you to slot the bag down the handle of a rolling suitcase. You might make something of a backpack or front pack by slinging the thing from the shoulder pad but this would best be left up to the individual experimenter.
Around the front, the bag is reminiscent of yesterday's smaller Streetline case, with the addition of two clip locks to get a tight pack.
Inside, the unique folding internal dividers make another appearance. These open up the soft bag and make a more rigid box shape for carrying bulky gear. You get two of them so make up your own pattern of whatever goes in there. If that includes paper rifle cartridges you might want to plan for a bit more time spent in the airport security scan line than the other travellers...
Plenty of space for an iPad, plenty of space for batteries, cards, chargers, flints, and touch-hole picks. Whoops, there we go again...