I'm looking for a small bag that doesn't cost a fortune that would attach to the rear slots on a Brooks saddle. I just want to be able to carry my keys, a couple of tools and other small things in it. I have the Champion Flyer B-17 with springs so the under saddle bags readily available won't really work. I've seen some new bags coming out from Brooks but they are very expensive. I don't really what material they are made of.