KI

The KI (pronounced "key") is a device from the Myst continuum that facilitates communication between the worlds. It is included in some PPC communicators. The exact design varies between agents, but is usually a preexisting device with the KI added into it. For example, Agent Tawaki owns a cellphone integrated with a KI, while Agent Fritz has a Star Wars comlink with integrated KI.

More about KI at D'ni Wiki.