The present invention relates to a medicament delivery device comprising a housing (10, 12), which housing (10, 12) is arranged to accommodate a medicament container (20), which medicament container (20) comprises a medicament delivery member (134)； a power unit (74) interactively connected to the housing comprises a force element (82) and a plunger rod (76) which is arranged to, upon activation, move linearly in the proximal direction and act on said medicament container (20) for expelling a dose of medicament through said medicament delivery member (134)； and a holding member (56) connected to said power unit and to said container holder. The invention is characterised in that the plunger rod comprises at least one first guide-and-stop element configured to interact with at least one second guide-and-stop element on said a holding member for limiting the linear distance the plunger rod (76) is capable of moving during expelling of medicament and which distance corresponds to a dose volume.本發明有關藥物輸送裝置，包含外殼(10、12)，該外殼(10、12)被配置來容納藥物容器(20)，該藥物容器(20)包含藥物輸送構件(134)；動力單元(74)，互動地連接至該外殼，包含力量元件(82)及柱塞桿(76)，該柱塞桿被配置成於啟動時在該近側方向中線性地運動，並作用於該藥物容器(20)上，用於經過該藥物輸送構件(134)排出一劑量之藥物；及固持構件(56)，被連接至該動力單元及至該容器夾具。本發明的特徵為該柱塞桿包含至少一個第一導引及止動元件，其被建構成與該固持構件上的至少一個第二導引及止動元件互相作用，用於限制該柱塞桿(76)在藥物之排出期間能夠運動的線性距離，且該距離對應於一劑量體積。
