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 these can be converted into an energy weapon, which has devastating effects on Cybermen. (DW: The Next Doctor)