KOSEKOMA 0099 - Lissajous Figure Ring (Size 9, 19.0 mm) #001: Circumference 59.5 mm / 2.34 inch. Hole diameter 19.0 mm / 0.746 inch. USA/Canada size 9. Japan size 18. Height 5 mm / 0.2 inch.
You can order another size of the ring
Size 8.5, 18.5mm
http://shpws.me/Ik0C