8mm celtic knot brushed center genuine tungsten carbide wedding rings. Hypoallergenic, durable, scratch resistant, cobalt free & comfort fit design. Symbol of love, suitable for Wedding, Engagement, appointment, feast, graduation & birthday gift. A velvet box helps to store the ring much longer. 30-day size exchanges or money back guarantee. If you have any question, please feel free to contact us or post into "Customer Questions & Answers" at the bottom of this page.