This looks like its just an error with the picture that is used, but I thought I would share anyhow. Is it possible its a new Christmas/Holiday bundled deal coming?
https://www.games-workshop.com/en-US/Necromunda-Terrain-Collection-2017
The Necromunda Refinery Collection is supposed to be 3 sets of the Promethium Refinery kit as seen here
but somehow the pic at the top of the page slipped in.