We provide constant wattage Series type heat tracer that use single or multiple resistive conductors to create a heating circuit. Power output of these cables is relatively constant and as voltage is applied, the power output is determined by a combination of the length of the cable and the overall resistance of the conductor. heating cable’s current and resistance is equal to all length heating cable, so the heating value of each unit is equally, not result in the power of terminal end is lower than beginning end with the increasing length of heating cable, so it is suit for long line pipes and large diameter pipe’s heat tracing or temp. maintenance, the cable can NOT cut to be length.