That's a great deal for an 8 TB drive, well under the usual market cost. They're standard PMR drives, I also heard they were WD Reds.
Got mine last Thu and cracked it open, it is indeed a WD Red 8 TB drive. I've seen some speculation that these drives are rebadged HGST 8 TBs, but comparing to my HGST 8 TB, the WD has a slightly different casing and completely different PCB. Could be a vintage/revision difference, though.
Drive works like a charm, much quieter and much faster at reads/writes than the old WD Red 4 TB it replaced in my system.
Wind, Sand and Stars.