It is not merely a transport safety part but a functional inner-cap cover that prevents the feed from drying out. If the cover is damaged or missing, the fountain pen should be sent in for repair, since Montblanc does not release spare parts in order to prevent assemblies cobbled together from original parts. On some models like the StarWalker the part is sometimes declared as merely a design element, because the model is operated with cartridges; on classic piston fillers, however, it is functionally necessary. Besides direct shipping, private workshops also offer repairs.