This device is for unshielded cables of 1, 2, 3, 4, 6, 8, 12 twisted pairs. This can replace AF and T networks and meets most requirements of medium-speed telecommunications, industrial control and input/output data links. Supplied with two sets of user-configurable cables. Also supplied are the 46ZZ calibration adaptors with each CDN. The whole system is supplied with a ground plane complete with spring clips to grip the CDN and an appropriate earth lead.