A sub-assembly of a medicament delivery device comprising a propellant source 26 having a reservoir (46, Fig 4) for containing a propellant and a stem 48 for dispensing propellant from the reservoir, the stem extending axially along a longitudinal axis and having an open outlet end 54 and a bore 50 therethrough that is in fluid communication with said open outlet end and is selectively in fluid communication with said reservoir (46, Fig 4). The sub-assembly also comprising a spray head member 68 attachable to the stem 48. The spray head member is arranged to radially deflect propellant passing through the bore of the stem relative to the longitudinal axis. Also defined is a further sub-assembly which is characterised by a continuous seal 66 extending around the external perimeter surface of the stem and also by a retainer member 68 with a spigot 70 extending into the bore 50 of the stem 48.
