KOSEKOMA 0101 - Lissajous Figure Ring (Size 9.5, 19.4 mm) #002: Circumference 60.8 mm / 2.39 inch. Hole diameter 19.35 mm / 0.762 inch. USA/Canada size 9.5. Japan size 19. Height 5 mm / 0.2 inch.
You can order another size of the ring
https://www.shapeways.com/shops/kosekoma?section=Math+Jewelry+-+Rings&s=0