Abstract: A device to join up cable sheathings comprises a chamber and a shaft. The shaft houses the cable and is connected in an electromagnetically impervious way to a rear part of the chamber. A front part of the chamber is itself designed to be connected in an electromagnetically impervious way to a casing, for example a connector casing. The conductive surface providing for the impervious electrical continuity between the periphery of the shaft and periphery of the chamber is outside the chamber. This makes it possible to give the internal diameter of the shaft a value that is substantially equal to that of a casing to which the front part of the chamber must be connected.