Low surface area conductive carbon blacks are a new set of products. Conductive carbon blacks, superconductive furnace or EC-blacks are characterized by a very high specific surface area. Although Janzen＇s formula, for the calculation of the critical volume fraction, only uses structure as determining parameter low surface area very high structure materials have not been produced till now. Those carbon blacks impart in addition to the required conductivity also the typical properties of a low surface area high structure carbon black: very good incorporation, easy mixing and dispersion and very good extrudability. Water adsorption is very low. The paper further investigates The-dielectric property balance and the use of those blacks in the improvement of heat generation in microwave cure.