I need to apologize for not explaining the product properly. It's like a plugmold.
Here: www.panduitncg.com/whatsnew/TG_news_release.asp
The ad shows 15 #12 THHN in the top section. "cables" was in a quote from them.
By 4 wire circuits, I meant 3Ø, 3 hots, one neut 120 v circuits (probably nonlinear to boot) All conductors are current carrying conductors.
What kind of 4 wire circuit has only 2 current carrying conductors??