A dose indicator device for a pressurised metered dose inhaler comprising: an inner wheel, an annular outer wheel, an actuator and a housing; the inner wheel comprising a plurality of primary indexing teeth and a flexible drive arm; the annular outer wheel comprising a plurality of secondary indexing teeth on an outer face of the annular outer wheel; the inner wheel and outer annular wheel being located at least partially within the housing such that the inner wheel and annular outer wheel are rotatable about a common longitudinal axis of rotation; the actuator being movable in a plane perpendicular to the longitudinal axis of rotation to engage the primary indexing teeth of the inner wheel to rotate the inner wheel; the housing being fixed relative to the longitudinal axis of rotation and comprising a deflector; the deflector being configured such that, on rotation of the inner wheel, the flexible drive arm is intermittently deflected by the deflector and is thereby brought into contact with the secondary indexing teeth so as to rotate the annular outer wheel about the axis of rotation; wherein the housing further comprises a first flexible restraint which engages the inner wheel to restrain rotation of the inner wheel when not being rotated by the actuator and a second flexible restraint which engages the annular outer wheel to restrain rotation of the annular outer wheel when not being rotated by the inner wheel; and wherein the second flexible restraint is engagable with the secondary indexing teeth of the annular outer wheel; wherein the housing comprises a mounting aperture for the inner wheel enabling the inner wheel to rotate therein relative to the housing; and wherein the inner wheel comprises a plurality of indentations on an outer face of the inner wheel which are engagable by the first flexible restraint and wherein the plurality of indentations form the bearing surface of the inner wheel in the mounting aperture. an inner wheel, an annular outer wheel, an actuator and a housing; the inner wheel comprising a plurality of primary indexing teeth and a flexible drive arm; the annular outer wheel comprising a plurality of secondary indexing teeth on an outer face of the annular outer wheel; the inner wheel and outer annular wheel being located at least partially within the housing such that the inner wheel and annular outer wheel are rotatable about a common longitudinal axis of rotation; the actuator being movable in a plane perpendicular to the longitudinal axis of rotation to engage the primary indexing teeth of the inner wheel to rotate the inner wheel; the housing being fixed relative to the longitudinal axis of rotation and comprising a deflector; the deflector being configured such that, on rotation of the inner wheel, the flexible drive arm is intermittently deflected by the deflector and is thereby brought into contact with the secondary indexing teeth so as to rotate the annular outer wheel about the axis of rotation; wherein the housing further comprises a first flexible restraint which engages the inner wheel to restrain rotation of the inner wheel when not being rotated by the actuator and a second flexible restraint which engages the annular outer wheel to restrain rotation of the annular outer wheel when not being rotated by the inner wheel; and wherein the second flexible restraint is engagable with the secondary indexing teeth of the annular outer wheel; wherein the housing comprises a mounting aperture for the inner wheel enabling the inner wheel to rotate therein relative to the housing; and wherein the inner wheel comprises a plurality of indentations on an outer face of the inner wheel which are engagable by the first flexible restraint and wherein the plurality of indentations form the bearing surface of the inner wheel in the mounting aperture.