Using this heat shrink is easy. First, choose the right size for your cable. Slip the heat shrink onto the cable before you do any wiring or soldering. Then, use a heat source like a heat gun or a lighter (be careful with the flame) to apply heat evenly around the heat shrink. As it heats up, it will shrink tightly around the cable, protecting it. When using a lighter, keep it moving to avoid overheating and damaging the heat shrink. After use, store the zip - lock bag in a cool, dry place to maintain the quality of the heat shrink. If you notice any signs of damage like cracks or tears, don't use that piece as it won't provide proper protection.