[twobjshelbys]

16 gauge twisted wire insulation. Get it in 25' coils at auto places or Radio Shack or other electronic supply places. Many colors available, including black, blue, red, white, orange, yellow, etc. Strip off the insulation from a piece of the wire and thread your safety wire through the insulation.

For clear tubing try a hardware or aquarium supply place thin air lines but I've never seen anything as thin as the wire insulation.