First Steps: Spyglass Piston

I think I found both a cooler and a sturdier idea instead of String.
I call it a spyglass piston. It is similar to the spyglass telescope, that is used in many pirate films, because it collapses into a small cylinder, but can be fully extended to most of the length of my arm (hopefully). It works using progressively smaller hollow cylinders of metal, connected with rubber stoppers attached to the individual pieces. They are progressively smaller because it would allow all of the pieces to fit inside each other, so that when they are compressed, it is the length of the largest piece, and when they are fully extended, it is the length of all of the piece’s lengths added up. The rubber stoppers would be glued, probably with industrial glue, to the ends of the cylinders because the rubber would be able to stop the air from leaving or entering the piston. Each rubber stopper would be attached to only one side of one metal cylinder. Each cylinder would have two stoppers and one would be on the inside while the other is on the outside of the cylinder.