A ring within a ring, one turning on the other. The dragon design is a 10th century pattern from the Isle of Man.
These rings are NOT adjustable, and are the following sizes:
XS = 16.25mm dia., US size 5 ½
S = 18.75 mm dia., US size 8 ¾
M = 19.75mm dia., US size 10
L = 21.25 mm dia., US size 12 ¼