Cyber-chest pack
As observed by ArcHivist Hegelia, Cyber-chest packs, or simply chest packs, were used by primitive Cyber-subspecies before being replaced by the chest units of the CyberNeomorphs. (AUDIO: The Cyber Nomads)
The Controller of the CyberTelosians was distinguished by his lack of a chest pack, which Hegelia claimed he did not need, and a special cranium design in place of the Cyber-helmet's side handles. (AUDIO: The Cyber Nomads, TV: The Tomb of the Cybermen, PROSE: The Power Behind the Throne)
The CyberNomads sported chest packs which were used to operate their energy weapon at the front of the cranium bulge. (AUDIO: The Cyber Nomads, TV: Revenge of the Cybermen)