A digital camera includes a CPU. A double wound lamellar ring is arranged outside and around the flap in a peripheral groove of the flap. The positioner has a sensor to measure the actual position achieved by the positioner. Finally, the system directs the flow of air into the fan exhaust so that the noise is attenuated by a reduction of turbulence in the fan exhaust by the flow of air. In one embodiment, the IED is a digital electric power and energy meter, which operating ranges for supply voltages and supply currents of electrical services may be adjusted to match pre-determined ranges for input signals of a data acquisition system or a data processing module of the meter. On the side of the anchor plate facing away from the open air side, a seal having tension elements running through it and having a sealing plate are arranged, the sealing plate being fixed in place on the side facing away from the anchor plate opposite the anchor body against longitudinal displacement.