Be course I think that a ring must be smooth, there are a lot of Meshes Points: 331.677 Edges: 994.782 Faces: 663.040 I have made it, so the logo - the flat part of the ring - can be set on the table from the printer, I think that this should be good. The sizes are in millimeters, the diameter inside. I think the most current sizes are 15, 16, 17, this are the numbers.