NEHZUS Jewelry Mens Womens Stainless Steel Promise Rings Custom Engraving Material:316L Stainless Steel.Width:6mm for men , 4mm for women Can be engraved on the Inside,please keep the letters within 5 characters Health certification does not contain harmful elements of "nickel" Best gift for couples,him,her or someone special,anniversary,engagement,valentines,or just because If you have any further question, please post into "Customer Questions & Answers" at the bottom of this page.or send us email,thanks