According to MonkeyDude1313, they are. Here, in this post, you can see his video on the QJ 4x4x4 and QJ 5x5x5 review. Also, here is my Mini QJ 4x4x4 post here.
So, uh here are MonkeyDude1313's videos.
Yeah. He calls them Cleffert's. They're actually QJ.
QJ 4x4x4 Video
QJ 5x5x5 Video