Durban Poison x Bubba Freeze (F4?), from Profile of ReBoMaN®seeds - Strainly
Not sure on the Bubba Freeze he used; he had it listed as F4 when I ordered from him over a year ago, but F2 now. He included the Durban Freeze as a freebie that he said he was testing, so it might not be a good sign that it’s not listed among his seeds for sale now. On the other hand, he might just have taken a year and a half to actually get around to listing it, he’s pretty laissez faire about his seed business from the looks of things. For all I know, maybe it’s gotten him so high he can’t get off the couch. 
I grew 2 of them, lost one and failed to cull this male because I couldn’t tell that it was one until a week into flower.