Originally Posted by dh024

You won't be able to attach a light to these panniers, so I would look back to your rack. What rear rack do you have? My Old Man Mountain rack had no mount, but it does have a big platform. If your rack does, too, it is easy to simply drill a hole near the back and screw on a short piece of 1" wooden dowel (pointing straight down). Then use a seatpost mount to attach the rear light.

And to answer your other question, yes, the Arkel Dry-Lites are 100% waterproof. I did a week in southern BC last spring and it pretty much dumped on me the whole time. But no leaks whatsoever. It can actually be a problem if you want to dry stuff out, in fact - you need to carry a mesh bag to lash on top of the panniers for when the sun comes out.