Medicament delivery device

The present invention relates to an medicament delivery device (10) having a proximal (11) and distal end (12) and intended for use in combination with a disposable container (20) having a distal and proximal end and comprising at least one chamber in the proximal end for a liquid medicament encapsulated in the container (20) by a movable plunger (26). The medicament delivery device (10) comprises: an elongated housing comprising a proximal housing section (13) and a distal housing section (14), said proximal housing section is configured to accommodate the disposable container (20); an elongated plunger rod (30) configured to be in contact with said movable plunger (26); and a drive mechanism arranged in said distal housing section (14) in order to, when the medicament delivery device (10) is activated, apply a force in a proximal direction via said plunger rod (30) acting on said movable plunger (26), wherein said elongated plunger rod (30) comprises an outer periphery in which at least two axially separate