The Shadow Disk is a communications device used by the Shadow Cabinet, a covert team of superheroes.
 The disk is 4 inches in diameter and has an outer casing of unknown composition that renders it waterproof and shock-resistant.   The Shadow Disk's most distinguishing feature is the Shadow Cabinet insignia on one side.  Because of this, Cabinet operatives wear the disk as a badge attached to their clothing so they can identify each other in the field.   When off duty or undercover, operatives conceal their Shadow Disks to remain inconspicuous.   
The insignia on the Shadow Disk also serves as a touch sensitive interface.  Touching different sections of the insignia activates the disk's various functions. Naturally, the Shadow Cabinet keeps the proper operation of their disks to themselves for security reasons. Hence, without this knowledge, trying to use a disk is a frustrating experience. 
The Shadow Disk sends and receives transmissions via the Dark Flow, an otherdimensional realm of dark matter.  Hence, the disk does not experience the EM interference of conventional forms of communication.  The disk also permits operatives to communicate with each other or with Shadowspire (Shadow Cabinet headquarters) from anywhere on the planet.   When receiving a message, the disk makes a distinct chirp ("weep weep") to alert its owner.  If the owner is unavailable, the disk records the message on its voicemail.  The disk will later alert its owner about any recorded messages when he or she picks it up.
Besides communication, the Shadow Disk serves as a homing transponder to allow Shadowspire to the determine the location of the device and thus its owner.  Each disk has a unique signal, enabling easy identification of operatives in the field.   This signal also provides a lock for the Cabinet's Shadowslide to teleport an operative to Shadowspire or somewhere else.   Finally, the disk's insignia can glow when activated, thus serving as a flashlight. 
Being such valuable technology, the Shadow Cabinet goes to great lengths to prevent Shadow Disks from falling into the wrong hands. Anyone leaving the Cabinet is required to surrender his or her disk at the end of their service.  A notable exception was Telesthene, who was allowed to keep her disk by Dharma for his own arcane reasons. 
The Shadow Cabinet has been known to give Shadow Disks to allies who can be trusted not to misuse them. For example, Dharma gave Icon and Harm each a disk as thanks for helping the Cabinet win the Shadow War.   Otherwise, only Cabinet operatives have Shadow Disks.
Despite these precautions, unauthorized persons have acquired Shadow Disks. A recent example occurred in the Shadow War when Cabinet operative Oro lost his disk during a three-way battle between the Cabinet, Star Chamber, and Blood Syndicate.  The disk was discovered by Syndicate member Masquerade, who later used it to teleport to Shadowspire in order to ask Dharma for membership in the Cabinet. Dharma reclaimed the disk before rejecting Masquerade's petition. 
Links and References
- ↑ 1.0 1.1 1.2 1.3 1.4 1.5 1.6 1.7 Blood Syndicate #10
- ↑ Shadow Cabinet #7
- ↑ 3.0 3.1 3.2 Blood Syndicate #19
- ↑ Shadow Cabinet #9
- ↑ 5.0 5.1 5.2 5.3 Shadow Cabinet #1
- ↑ Shadow Cabinet #6
- ↑ 7.0 7.1 Shadow Cabinet #3
- ↑ 8.0 8.1 8.2 Shadow Cabinet #13
- ↑ 9.0 9.1 Shadow Cabinet #8
- ↑ Shadow Cabinet #15
- ↑ Blood Syndicate #20
- ↑ Shadow Cabinet #4
- ↑ Icon #20
- ↑ Shadow Cabinet #14