• Unequaled eternal protection. • Choice of two metals: copper and stainless steel. • Copper offers the ultimate in underground durability. Archeological digs often recover items made of pure copper in superb condition after 8,000 years. • Stainless steel is an alloy of iron, carbon, chromium, and nickel. The stainless steel used in Clark vaults is a premium grade alloy with high chromium and nickel content. The Gateway Arch in St. Louis is made of the same high quality alloy used to manufacture stainless Clark Vaults. Many common kitchen • accessories are available in stainless steel such as cookware, flatware and sinks.