The present invention provides a closable male luer connector (101) in which an inner portion (121) within the spigot (111) of the connector is movable from a sealing position to an open position on connection of the connector to a female luer connector (10). The movement of the inner portion may be caused by a screw thread arrangement comprising an outer lock ring (130) having an internal screw thread (133) and a corresponding screw thread (121k) on an outer surface of the inner portion (121).
