Operating as a data storage device, the Wrist Halo displays information such as text and maps[note 1] by a hologram projected from the wrist. The Wrist Halo has also been used as a radar, alerting Aki to the presence of Phantoms. Essentially, it is a prototype holo-distance-gauging device. The Spiritual Energy Positioning System, or SPS, scans for pre-programmed, specified spiritual energy reading by a SE sonar with a scanning radius of approximately 100 meters.
- When Aki Ross is overlooking Old New York, the map on the wrist halo is an actual map of the streets of New York as of 2001.