A dose indicator device 9 for a pressurised metered dose inhaler (1, figure 1) has an inner wheel 11, an annular outer wheel 12, an actuator 13 and a housing 70； the inner wheel has primary indexing teeth (22, figure 5) and a flexible drive arm (23, figure 8)； the outer wheel has secondary indexing teeth (33, figure 8) on an outer face of the outer wheel. The inner and outer wheels are located at least partially within the housing such that they rotate about a common longitudinal axis (21, figure 8), with the inner wheel nested inside the outer wheel. The actuator moves vertically to engage the primary indexing teeth to rotate the inner wheel； a deflector (59, figure 6) intermittently deflects the drive arm into contact with the secondary indexing teeth to rotate the outer wheel about the axis of rotation. Indicia may be present on both wheels (figure 9) to indicate the number of doses delivered or remaining.
