A polyester Mylar film heat shrinkable cable end cap is a type of cable accessory used to protect and seal cable ends. The end cap is made of a polyester Mylar film that is heat shrinkable, meaning it can be applied over the cable end and shrunk tightly around it with the application of heat. The end cap provides a protective barrier against moisture, dust, and other environmental contaminants that can damage the cable over time. The use of heat shrinkable end caps is common in the cable and wire industry, particularly for outdoor and underground applications where cables are exposed to harsh environmental conditions.