History
Doctor Doom had one of these devices onboard his Flying Fortress. It allowed to send his image and voice from a safe point so that the listener could not trace him.[1]
He used it once to confer with his prisoner Invisible Girl - he had previously sent a Doombot, but she had identified it as a decoy and destroyed it. Doom then showed from a distance, the image of his greater-than-life head in a floating ball at the height he would have had. After speaking for a while, the round image was replaced with an image of Doom's full body - either a new robot, following the conversation seamlessly, or Doom himself in person, or the sphere had the ability to show full-body images. Due to the nature of the conversation, the Invisible Girl left.[1]Notes
Name never revealed