10mm Black Tungsten Carbide Ring with Six(6) Masonic Compass & Square Emblems (Full & Half Sizes 5-15) All our tungsten rings are Cobalt Free and stamped Tungsten Carbide on the inside of the ring All our Tungsten Rings are Comfort Fit Available In Full and Half Sizes 5-15 Lifetime Warranty - We've Been Selling Tungsten Rings for Nearly a Decade