ARCHIE | Black Tungsten Ring, Koa Wood and Inlay, FlatBlack Tungsten Ring with Koa wood and Black Carbon Fiber Inlay 8MM This Ring is made of high Grade tungsten carbide which provides excellent durability. Black Tungsten Ring with Koa wood and Black Carbon Fiber Inlay of the Ring. Ring Measures 8mm width for Men. Tungsten carbide rings are extremely durable and won't scratch or fade. This Ring is made of high grade tungsten carbide which provides excellent durability. It is cobalt free which offers