A breath actuated inhaler for delivering medicament by inhalation, comprising a housing having a mouthpiece and defining an air flow path extending from the mouthpiece through the housing; the housing holding a replaceable canister of medicament actuatable to deliver a dose of medicament into the air flow path, wherein the housing defines an opening in the air flow path and the opening is closed by a closure element connected to and replaceable with the canister. The closure element acts as a safety feature because it is only closed when the inhaler is used with a canister to which a closure element is connected the closure element carries an indication of the type of medicament in the canister to allow the user to recognise the type of medicament. A plurality of inhalers may be provided in which each given inhaler has an opening with a different shape and has a closure element with a shape which conforms with the opening of the given inhaler but which does not conform with the openings of the other inhalers.