THE INVENTION RELATES TO A MALE CONNECTOR FOR USE IN A CONNECTOR SYSTEM FOR CONNECTING CONDUITS FOR FLUID FLOW THERE BETWEEN. THE SYSTEM COMPRISES A MALE CONNECTOR AND A FEMALE CONNECTOR AND THE CONNECTORS ARE RELEASABLY INTERENGAGEABLE TO FORM A FLUID-TIGHT CONNECTION. THE MALE CONNECTOR IS ADAPTED BY A BARRIER (7), E.G. A DISC, TO CONNECT ONLY TO A STANDARD FEMALE SLIP LUER CONNECTOR. THE INVENTION ALSO RELATES TO AN INFUSION SET INCLUDING THE MALE CONNECTOR. FIG. 3