Haven't the Ringwraiths always been fairly big, imposing models? They should certainly be on the usual 25mm.

I think the old Ringwraiths used to be human sized. 25 mm tall, give or take. These look like they are at least 35 mm. I was tempted to use them as evil human captains, but if they are like ogre size that kind of does not work.

This was the only picture I could find, but illustrates my point well enough, Khamul is certainly a bit taller than the plastic Minas Tirith bloke, although part of that may be the common metal vs plastic discrepancy. Mouth of Sauron is quite large too I think, so I'm still tempted to have one of these as a Black Numenorean. Having now seen a few more pictures of the new Dol Guldur wraiths however, those certainly are substantially bigger, towering over normal infantry. Can't remember if that was the case in the films too...