Ur-box
An Ur-box was a complex device of Time Lord design. It operated by recording events of a specific point in the timeline. After which, it projected that data and information into the Time Vortex thus sending false information toe time scanners of time active factions. This allowed the users of the Ur-box to operate without being detected and thus change a point in the timeline.
There were, however, a number of problems with the technology. The first was that it had a limit sphere of influence which necessitated that there would have to be no excursions outside the field. Furthermore, events within the field needed to be match those of the Ur-text and thus individuals were required to act out events from the "real" timeline.
Xenaria made use of an Ur-box during the events surrounding the breaching of the time loop surrounding Planet 5. (EDA: The Taking of Planet 5)