Infostamp

An infostamp is a cylindrical memory bank. They project the contained information like a modern film projector.

The Cybus Cybermen made use of infostamps to transmit information to their databanks and inserted them within their chest cavity in order to learn information on a certain subject. Part of the information stored on these infostamps was stolen from the Daleks while both they and the Cybus Cybermen were in The Void.

A Cyberman was apparently able to detect if an infostamp was corrupted simply by holding it with the cap at one end open; it was similarly able to repair the infostamp by doing much the same thing.

The core of an infostamp was a highly potent energy unit - breaking the seal of the core released a dangerous energy beam. Thus, they could be used as an energy weapon which had devastating effects on Cybermen. (DW: The Next Doctor)