A Potter-Bucky device for a radiation image recording apparatus in which an image recording medium is exposed to radiation which has passed through an object in order to record a radiation image of the object on the recording medium includes a grid which is movably supported between the object and the recording medium and is reciprocated parallel to the recording medium. A stop element which can be accessed from the housing outer face and which can be adjusted in the closing direction is arranged in the spring chamber, the spring element end that faces away from the closing direction resting against the stop element. The ball also has a rotational speed cue formed from a plurality of spaced panels arranged parallel with the alignment cue. Such interconnector-mounted fuel cells can be stacked together to increase the voltage output of the fuel cells which can be used to power a load. Methods and compositions for inhibiting an HIV infection are also disclosed. The matching capacitors connected to the first and second center conductors respectively have Q factors of 400 or larger.