This device is fitted to the Guidance System and Directional Unit. When installed it uses a random field frame to ensure that the destination coordinates are random. It also keeps a TARDIS from getting a lock on galactic zero center. Every time it is activated the operator must input a random seed setting. This seed number is the basis of the improbability algorithms. It is illegal for a Time Lord to own or construct one of these devices. The Randomizer can be overriden by deactivating all of a TARDIS' travel circuits and inputting space-time coordinates.