This the other side of the "3-way bags" with the multiple pockets under the flap. I dont know if the "Pro II" model (that is pictured on the web site) has the same velcro bag attachments that allow the necessary adjustments  to fit the bike, although they might work just as well.

Well, I've had them on for a couple hundred miles so far with no issues at all. I like the fact they are narrower than most bags ( about 4" thick), but hold quite a bit. Supposedly waterproof material that remains to be seen. On the left side I have sunglasses, a camera, and a 20 water bottle. On the right (larger bag) I have a small tool kit, first aid kit, extra gloves & hat plus rain gear & another 20 bottle of water and bungee cords with a little room to spare. If you wanted to use that bag as a cooler, you could easily pack lunch, drinks, and ice/ blue ice for two. They secure to an under seat harness similar to the "hooker " rig (bungee points  ) with wide HD velcro straps that I can't forsee coming loose if you limit them to a reasonable load wt. Since they are designed with offroad 4 wheeling in mind I suspect they will hold up OK -they seem very well made. You  can also switch sides if you like. I actually ordered another set so I'd have two of the larger bags that match, although I may just leave the ones I have now as they are and have a "spare" set. For both sets (including shipping) less than $20