NCT 127 is the second sub-unit of the South Korean boy group NCT formed by SM Entertainment. Their unit name is a combination of the acronym Neo Culture Technology and the number "127" which represents the longitude coordinates of the city of Seoul. Debuted on July 7, 2016 with the mini album NCT #127, their initial member consisted of 7 members: Taeil, Taeyong, Yuta, Jaehyun, Winwin, Mark, and Haechan. Doyoung and Johnny later joined forces in December 2016, ahead of the release of the mini album Limitless in 2017. Jungwoo was then introduced as a new member in September 2018, followed by the studio album Regular-Irregular in October 2018.