Abstract: A device for dispensing an aerosol from an aerosol module containing aerosol under pressure wherein there is a cocking device for readying it for release of the pressurized aerosol, a sear for retaining the cocking device in a non-operative position following readying and a vane operable by inhalation on the part of a user to disable the sear to thus release the cocking device to effect expulsion of aerosol from the aerosol module. The cocking device further includes a recocking member that is automatically releasable at the end of the discharge cycle to permit a valve in the module to return to its disabled position and ensure complete refilling of a metering chamber.