Heat shrink, or shrink tubing, is a very common material used in the fabrication and assembly of cables, cable harnesses and the assembly of different cables and connectors together.

Heat shrink is a material usually found in the form of a hollow cylinder or tube, with a starting diameter that shrinks down to a much smaller diameter when heat is applied to its surface.  When heat is applied, the tubing shrinks down to a smaller diameter. Each size of tubing has a limit to what it will shrink to, and once that limit is reached it is recommended to no longer apply any more heat, as any additional heat can begin to degrade the quality of the material.

Heat shrink is an insulating material, which makes it a good source to clean up any exposed soldering joint in cables or harness that are not desired to be exposed. If desired, it can help protect exposed connector ends.  It works well in several different applications, as it conforms to objects, connectors and cables, while it shrinks to create a nice seamless transition.

Heat shrink is manufactured in different sizes, densities, colors and lengths. It often can be effective to use the different colors and sizes to group together several different wires into groups and to help organize the distribution of large numbers of wires.