A clamping device for attaching to an external fixation element of an external fixation system includes a first jaw having an inner surface and an outer surface and includes a second jaw having an inner surface and an outer surface, with the inner surface of the first jaw and the inner surface of the second jaw together forming a passage configured to receive the external fixation element of the external fixation system. A locking system is engageable with the first and the second jaws. A portion of the locking system is moveable relative to the first and the second jaws between a first position where the locking arrangement is configured to prevent release of the external fixation element having a first size from between the first jaw and the second jaw and a second position where the locking arrangement is configured to prevent release of the external fixation element having a second size from between the first jaw and the second jaw.