What ArcHivist Hegelia termed headblocks were a component of the Cyber-helmet of certain Cyber-subspecies, appearing at either side of the faceplate and connected to the cranium bulge by side handles. (AUDIO: The Cyber Nomads)
The Cybermen of the early CyberFaction which waged the first invasion of Earth sported striated headblocks. (TV: The Invasion) These headblocks were retained by their descendants, the CyberNomads. The nomad Cyber-Leaders were distinguished by black side handles and headblocks on an otherwise silver Cyber-body. (TV: Revenge of the Cybermen)
The CyberNeomorphs, believed by Hegelia to have been created as a result of the combination of Cyber-technology between the CyberNomads and the CyberTelosians, (AUDIO: The Ultimate Cybermen) also sported headblocks. Unlike the nomads, however, their Cyber-Leaders were distinguished only by black side handles, with their headblocks matching the silver of their bodies. (TV: Earthshock et al.) They were followed in this regard by the CyberIsomorphs. (TV: Silver Nemesis)
Cyber-Warriors of the far future Cyber-Wars sported similar headblocks. (TV: Ascension of the Cybermen)