For the production of steel with an EAF (especially, also, for stainless steel, as shown at CORUS Engineering Steels in Stocksbridge), the RCB system of VAI FUCHS (Refining Combined Burner) represents an important step forward, in many respects, for the injection of oxygen. The constitution of the system, its working mode and its advantages are described. This innovative solution is already applied in the case of quite a number of furnaces.