Nike SB's line has traditionally been more willing to reference illicit substances and events than others within the brand. SBs have celebrated cannabis holiday 4/20 intermittently over the years, with pairs like the "Skunk" Dunks releasing around April 20.
It appears that Nike SB may have another of those designs in the works with the pair shown here. It's not explicitly clear what theme they're aiming for, but the graphics decorating the upper vaguely resemble weed.
If this is indeed Nike SB's "4/20" Dunk for 2017, readers should expect the pairs to start arriving at retails in the coming weeks.