was posted on SM's official YouTube Channel, featuring the NCT members and trainees practicing in the studio.
Filmed on December 22, 2017, and dressed in all black, the boys can be seen eagerly going over their moves from "Black on Black". They have some crazy footwork and this video shows why they're such talented dancers.
SEE ALSO: NCT drop performance version MV for 'Black on Black' with all 18 members
Meanwhile, NCT recently left for Ukraine to film their new MV.