zoethecus stand - what size cone feet?

I have a zoethcus stand with five black slabs (including the top one) I picked up a while ago. It did not come with feet but has the threads for it.

Does anyone know what size adjustable cones would fit those?

I was going to get cones and the little washer things for the cones to stand on. That's my current set up for my speakers. Assuming that is recommnedable for the stand as well?

Thanks very much.