A connector having a body 1 with a central throughway in which a tube T is received. A collet 30 within the body has a plurality of flexible legs 32 arranged to grip the tube T if a force is applied to withdraw the tube. The connector further comprises at least one first tooth 14, the first tooth having a gripping edge in a plane angled to a plane perpendicular to the main axis of the connector, and being mountable with respect to the body so as to be non-rotatable about the main axis X. The at least one first tooth increases the grip of the connector of the tube.
