KALANI Flat Tungsten Carbide Wedding Band with Rare Koa Wood Inlay and Polished Edges - 6mm - 10mm The rich, natural inlay of this Tungsten Carbide ring by Thorsten is made of rare 100% authentic Hawaiian Koa wood which cannot be cut down under Hawaiian law. Only trees that have fallen on their own can be harvested, making Koa one of the most expensive woods in the world. Engraving available! Does Not Delay Order Includes Thorsten Lifetime and Lifetime Sizing Warranty (excluding re-engraving) Available in 6mm, 7mm, 8mm, and 10mm widths. Perfect for couples who want a matching set! Tungsten Carbide—the newest and strongest metal for jewelry that does not scratch easily. Note that the wooden inlay is protected by a resin that can be scratched. Comfort Fit – domed interior band slides over the knuckle easier with less friction