Abstergo Ring

An abstergo Ring I made using Boolean option in 3DSMAX.
Scaled so that it is 11mm high and its inside diameter is 19.57 mm.
Adjust by using a piece of paper you put around your finger and measure it, now you have the perimeter use :
Diameter = perimeter / Pi
Take this number and add 2mm which is the thickness of mine.
The one in the photo is made of Bronzefill