This is a uniquely designed ring made with materials that are less likely to cause metal allergies. It is silver925 with 18k gold plating. This does not guarantee that all individuals will be free from metal allergies. Size: Approximately US size 4.5 to 8.5 (Japanese size 9 to 18) As it is a soft metal, you can adjust the size yourself. Excessive adjustment or frequent size changes may cause damage.