In a modular medicament delivery system, a dispenser housing has a support block with a well and an orifice communicating with the well. A first container assembly includes a valve stem shaped to be received by the well in the support block. The first container assembly has a first exterior shape. A second container assembly includes a valve stem shaped to be received by the well in the support block. The second container assembly has a second exterior shape that is different than the first exterior shape. An insert member is adapted for mounting to the dispenser housing in the cavity and defines an interior space shaped to receive the second exterior shape of the second container. Methods of assembling the system, a system kit and a device are also provided. A medication delivery device includes first and second end pieces and a collapsible chamber disposed therebetween.