A flange (3) for sealing an opening (1) of a fuel container (2) of a motor vehicle maintains an electronic component (9) which is arranged on the external side (5) on a carrier (12). The carrier (12) is embodied as a single piece and has a heat-conducting element (13) which can penetrate the wall (4) of a flange (3). The heat-conducting element (13) dissipates the heat which is produced by the electronic component (9) to the inside (7) of the fuel container (2).