A pressurised metered dose inhaler (1) comprising: a reservoir (2) for containing pressurised product, a valve (9) having an inlet (11) communicating with the reservoir and an outlet (14) through which product is dispensed in use, a piece of magnetisable material (5), an armature (8) extending into proximity with the valve, and an electromagnet (7) surrounding at least a portion of the armature. Wherein the armature is coupled to, or forms part of, the valve such that controlled energisation of the electromagnet causes the armature to be either attracted to or repelled from the piece of magnetisable material one or more times to operate the valve for a controlled time period to effect dispensation of a metered dose of pressurised product from the reservoir through the valve outlet.
