Infostamp

An infostamp was a cylindrical memory bank. They projected the contained information like a modern film projector.

The 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 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)