According to Section 10(1) of the German Patent Act, a patent has the effect that any third party that does not have the consent of the patentee is prevented from offering or supplying a component relating to an essential element of the invention. According to the recent Flügelrad decision of the German Supreme Court (X ZR 48/03 dated May 4 2004), in assessing what is an essential element of the invention, only components that have a functional interaction with other elements of the patented device can infringe the patent.