Abstract: A plug-in module is described; one side of this incorporates four spring leaves (6, 6') that can be deflected slightly outwards and which are arranged on one side in a tulip shape and which, on the other five sides surfaces (2 to 5), can be snapped onto a similarly constructed plug-in module. The side surfaces incorporate ridges (8, 8') which can be either continuous or segmented. On their inner sides, the spring leaves are provided with corresponding connecting elements (7, 7', 7") which snap behind the ridges described above. The production of a connection between two plug-in modules is effected first by a slight outward deflection of the spring blades from their rest position and by them subsequently snapping into position behind the ridges described above. The plug-in modules entail the advantage that even after a long time and frequent use, they can still be connected to each other easily or released from each other with equal ease.