When enabled this system prevents a TARDIS from materializing around or embedding itself in an object and automatically chooses a secluded and reasonably safe materialization site. This selection is based on data collected one micro-second before re-materialization begins. The Selector can be fine tuned to prevent a TARDIS from materializing on the edge of a cliff, or even on planets where the local technology falls below a pre-selected level. As with most systems the operator has the option of overriding the Selector.