Disclosed herein are cartridge assemblies (300) that include coding features (318) that help dedicate a medicament reservoir to specific injection devices. An exemplary cartridge assembly (300) comprises a cylindrical inner surface for holding medicament and a cylindrical outer surface comprising at its proximal end one or more stops configured as coding elements (318) protruding from the cylindrical outer surface. Each coding element (318) is configured only to engage a corresponding coding feature (330) on a dose setting and delivery mechanism (302), thereby allowing only the correct cartridge assembly (300) to connect to the dose setting and delivery mechanism (302).
