This invention provides a dispenser for a gaseous, gas borne or droplet substance contained in a source thereof, the dispenser including: €¢ a body with a mouthpiece €¢ a junction member in the body for the substance source and €¢ a breath actuable valve, for controlling the release of the gas or liquid containing or comprising the substance, the valve comprising: —‹ a flexible tube for receiving the said gas or liquid, the tube extending from a valve inlet connected to the junction member and having a portion which is kinkable for closure of the valve and movable to an open position in which the tube is un-kinked for opening of the valve and —‹ a member arranged for movement in the body by inhalation to un-kink the valve €¢ the tube being kinked to an obturating extent when the movable member is in a ready position and un-kinked when the movable member is moved on inhalation for release of the gas or liquid wherein: €¢ the movable member is or includes a flap arranged in the body for action of breath on it on inhalation €¢ the junction member, the flexible tube and the movable flap are a single injection moulding of plastics material and €¢ the movable flap is pivotally connected to the junction member.