A supplemental device for attachment to an injection device comprises an aligning arrangement for ensuring a predetermined positional relationship between the supplemental device and the injection device; and a securing arrangement for securing the supplemental device to the injection device.一種用於附接至注射裝置之輔助裝置,其包含:校準設備,用以確保該輔助裝置和該注射裝置之間的一預定位置關係;以及牢固設備,用以將該輔助裝置牢固至該注射裝置。