A containment system for installation internally along a conduit, for co-locating at least one sensing element and one or more communication media within the conduit, the containment system comprising: an elongate flexible body mountable on a wall of the conduit to extend longitudinally along the conduit, the body including: an elongate sensor cavity, extending longitudinally along the body, for receiving the at least one sensing element; and a shield portion including one or more elongate channels, extending longitudinally along the shield portion, each channel for receiving one or inure communication media.