Our products are with a kind of PTC material, which can be heated to keep the temperature. The electric current flows in, causes the cable to heat up and consequently raises the resistance value. When the PTC polymer reaches the transition temperature, its resistance value takes a step increase, which is high enough to cut off the current and keep the temperature from going any higher, and the purpose of self-temperature regulating is served. Self -regulating heating cables have been used in many fields. For example, roof and gutter frost protection, heat tracing of rails, snow melting of roads, industrial pipe frost protection, etc.