Joe, how much "protection" are your looking for? Or what is your version of strong?
You could go with a aluminum rod tube that is very strong but in my opinion way too heavy. On the other end you could use 2 rubber bands, maybe not the least bit protective.
I use a very thin plastic tube much like what they sell on this site. It is also like the plastic protective tubes used for florescent light (you can get them at the lumber yard.
Maybe give us some more info to work with then we can help you better.