The rings are made from a high-grade stainless steel with a hypoallergenic coating.
Sizing: The diameter mentioned in the description is the diameter of the inside of the ring. To figure out which ring fits you, please measure the broadest part of the finger which you want to put your ring on (either the knuckle or the base of your finger, depending on the shape of your finger). Next, pick the size that can at least accommodate that measurement. Please remember that the rings are made of solid steel and will not budge.