Benchmark Alternative Metal Cobalt Chrome 6mm Satin Band with Polished Center Men's Ring, Benchmark #CF56411CC. Authentic Benchmark cobalt chrome band with comfort fit, satin finish, and polished center ridge. Width is 6mm. Cobalt Chrome is a unique alloy blend that consists of cobalt and other substances to form a bright white alternative metal. It is as white as platinum, hypoallergenic, unbreakable, and scratch resistant. These bands are light-weight, inside round comfort fit and very comfortable to wear. This metal has been used in medical applications for years. Occasional polishing may be required.