The Raychem® Frostex pipe freeze protection system is designed to freeze-protect dry or weather-proofed, insulated, aboveground residential water pipes. The heating cable uses a self-regulating conductive core that reacts to changes in temperature. As the environment becomes colder, cable resistance decreases to generate greater heat. Conversely as the environment warms, cable resistance increases to produce less heat. Therefore, every inch of pipe and valve consistently receives the amount of heat needed to prevent freezing.