bobbin 110 is not shown for the purposes of clarity the spool 134 is arranged to rotate upon movement of the yokes 566 568 to effect delivery of a dose of medicament from reservoir 514 such that the number on the ribbon 5128 is advanced to indicate that another dose has been dispensed by the inhaler 510 the ribbon 5128 can be arranged such that the numbers or other suitable indicia increase or decrease upon rotation of the spool 5134 for example the ribbon 5128 can be arranged such that the numbers or other suitable indicia decrease upon rotation of the spool 5134 to indicate the number of doses remaining in the inhaler 510 alternatively the ribbon 5128 can be arranged such that the numbers or other suitable indicia increase upon rotation of the spool 5134 to indicate the number of doses dispensed by the inhaler 10 the indexing spool 5134 includes radially extending teeth 5136 which are engaged by pawl 5138 extending from a cam follower 578 of the second yoke 568 upon movement of the yoke to rotate or advance the indexing spool 5134 more particularly the pawl 5138 is shaped and arranged such that it engages the teeth 5136 and advances the indexing spool 5134 only upon the mouthpiece cover 528 being closed and the yokes 566 568 moved back towards the cap 526 of the housing 518 the dose counting.