Abstract: A training device (10) for training a user in the operation of an auto-injector that dispenses a medicament is described. The training device (10) comprises a housing (13), an actuation assembly (22) located within the housing (13), the actuation assembly (22) comprising a plunger (24) and a guide member (26), the plunger and the guide member defining, and connected by, a complementary first male profile and a first female profile. The plunger (24) is movable with respect to the guide member (26) along a first path defined by at least a portion of the first male or the first female profiles, the plunger (24) moving linearly between a start position and a finish position. The first path extends in a direction non-parallel to the linear movement of the plunger (24).