The Copper-Core line from All-Clad boasts both the superior heating qualities of copper and the easy-to-clean features of stainless steel. The pieces in this line are made using a patented five-ply construction in which the copper core is surrounded by layers of aluminum, interposed between layers of stainless steel. The perfectly polished outer layer of stainless is broken up by a ribbon of exposed copper as an added visual element. Available in sets or open stock. Lifetime Warranty. Made in the USA.