While it is possible to hide a TARDIS from the observational powers of Gallifrey by placing it near a Naked Singularity, a Grey Immensity, a Phantom Star, or a Dwindler, some operators might wish to have a greater choice of locations. Stealth mode was developed as a way to hide TARDISes located in less exotic time zones. When activated Stealth Mode disables a TARDIS's connection with the Prime Eye of Harmony and deactivates all non-essential systems. With the exception of basic life support, almost everything is made non-functional. This makes a TARDIS virtually undetectable to everything, including Gallifreyan scanning devices.