I ordered the Arkel Dry-Lites. Here's some info I got from the company:
The Dry-Lites seams are all sealed and the bags are completely waterproof. The Dry-Lites where design as rear saddle-bags but could be use up front if you use a front rack equipped with a plateform, such as the Old Man Mountain Sherpa front. The deck has to be at least 7 ½ inches long. These bags are designed to be extremely light, and as any piece of ultralight gear, they are definitely more fragile and they are mainly designed to carry “soft” gear like extra clothing, flip flops, jackets etc.. It is not recommended to carry heavy water bottles, mini stove, canned food etc.. These hard objects can cause wear and ultimately damage the bags.