material
-Copper
size
Open Ring size : inside circumference about 4.5 ~ 4.6 CM, thickness about 1MM, width: 0.5CM(min), 1.2CM(max)
ring size chart :
https://www.dropbox.com/s/uvbnnf2bgot7mix/%E6%88%92%E5%9C%8D%E5%B0%BA%E5%AF%B8%E5%B0%8D%E7%85%A7%E8%A1%A8.pdf?dl=0