A counter connector for mating with a connector, the counter connector having a hollow cylindrical housing. The counter connector comprises at least two, preferably three, of the following three types of locking means for locking the counter connector to the connector: a) Arranged on a perimeter on a cylindrical surface of the housing or of a sleeve located inside the housing, a counter engagement part in the form of a groove, a collar, or a series of radially extending apertures, recesses or protrusions, the counter engagement part being adapted to engage with at least one engagement part or at least one latching part of the connector; b) A counter latching part that can be deflected elastically in a radial direction of the counter connector and comprises at least one of a radially extending groove, collar, aperture, recess or protrusion adapted to engage with a latching part of the connector; and c) A counter thread adapted to engage with a thread of the connector. And a system comprising a counter connector according to one of the preceding claims and at least one connector that can be mated with the counter connector, wherein the connector is of one of the following three types: a) A push-pull connector; b) a break-away connector; and c) a threaded connector.