A source of gaseous, gas borne or droplet substance having: an innerpressurised container (1), a substance-release valve (2) device sealed acrossan end of the container (1), a spout (4) displaceable inwards of the container(1) against a spring of the valve (2) device for substance release； the sourcealso includes: an outer enclosure enclosing the inner container along itslength (12), at least partially its end (14) remote from the spout (4) andpartially at its spout end (19), the outer enclosure ADN the inner container(1) being arranged to react force for displacement of the spout (4) onsubstance release； a counter (20) accommodated within the outer enclosure forcounting substance release displacements of the spout (4)； and a window (22)in the outer enclosure for viewing the count of the counter (20).
