The name heat-shrink tubing pretty much sums up what it is and does: a plastic tube that shrinks permanently when heat is applied. How much it shrinks is determined by its shrink ratio, commonly ranging from 2:1 to 6:1. Think of heat-shrink tubing as the duct tape for electrical wiring on the factory floor. Heat-shrink tubing is versatile, easy to use, and finds wide applicability in maintenance and repair. Heat-shrink tubing can be used for preventive maintenance to avoid problems, and it is a wonderful tool for making minor repairs to cables and connectors.