where was this aforesaid series aired?
The series premiered for two series on Channel 4 after its addition to the catalogue Netflix purchased the programme
Black Mirror
The series premiered for two series on Channel 4 in December 2011 and February 2013. After its addition to the catalogue in December 2014, Netflix purchased the programme in September 2015.
what is the meaning of metalhead in black mirror "Metalhead" is filmed entirely in black and white, and follows the plight of Bella (Maxine Peake) trying to flee from robotic "dogs" after the unexplained collapse of human society. when was it premiered? The episode first aired  on 29 December 2017 is this a series? No, "Metalhead" is the fifth episode of the fourth series of the anthology series "Black Mirror"
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Black Mirror [SEP] Introduction
After its addition to the catalogue in December 2014, Netflix purchased the programme in September 2015. It commissioned a series of 12 episodes later divided into the third and fourth series, each comprising six episodes; the former was released on 21 October 2016 and the latter on 29 December 2017. A standalone interactive film titled "" was released on 28 December 2018. A fifth series, comprising three episodes, was released on 5 June 2019.