At the opening (3) for insertable electronic or similar cards in a housing (1) for electronic circuits a frame is mounted including separate frame parts (5, 5', 5'') having outer portions connecting to the edges of the opening. The frame can by its modular construction be adapted to an arbitrary number of shielding or cover plates (7) that are comprised in such cards and are placed or are to be placed in the opening. A simple mark-up of the position for a card can be easily made on a frame part located at the part opening for the card. The frame parts form together with the cover plates a whole continuous surface. Intermediate frame parts (5) divide the opening in part openings, each intended for only one cover plate. Elastic contact elements (27) are provided mounted in recesses in the frame parts to electrically connect adjacent cover plates to each other and a frame part to that cover plate or those cover plates which are located at the frame part. The contact elements provide a reliable elastic contact to edge surfaces of the cover plates by acting in the plane of the cover plates. Furthermore, contact springs (45, 45') connect the frame parts to the housing.