This is a Calvin Klein stainless steel ring. I purchased it at a department store and used it, but then stored it for a long time. I don't know the exact size, but based on my amateur measurement of the inner diameter of the ring being 16mm to 1.7mm, I estimate it to be around size 10 to 13. (This is for reference only.) The inside of the ring is marked only with "ck s/s". There are scratches on the surface. Please purchase with the understanding that this is a used item. It comes with a box and a small pouch. Thank you for looking. Calvin Klein Calvin Klein