This is an open ring design, so the size is adjustable as the ring doesn't form a complete circle. ● Material Stamped S925 ● Size Adjustable ring, approximately size 13 to size 20 (Japan size) Size 13 before adjustment ● Ring Maximum Width Approximately 1 millimeter I purchased this on Mercari, but it didn't fit my finger size, so I'm selling it. It's new and unused, as I only tried it on. #ring #mensaccessories