I read about these in the last issue of FLW Outdoors, then saw them at ***. You have to see the action of these things on a shakeyhead. They are totally sick 8-) !! The rings trap air so that they stand straight up in the water, and if you're kinda dancing them along the bottom they have an action that, well, undulates. You can fish them wacky style, but you'll be able to have a smoke waiting on them to get to the bottom if they're unweighted.
The photos below are of the color I've been getting my action on, called California Red. The top is almost a dark brown while the bottom is greenish. It's laced with red flake. IMO, this thing is the cat's behind. Gotta order some more.