DESC: Up until now All-Clad's excellent heat conductivity has been a result of an aluminum core. Another metal equally efficient when it comes to conducting heat is copper. All-Clad now has a complete line of copper core stainless steel cookware which uses bonded 5-ply construction to achieve culinary perfection. The copper core is exposed in an attractive band around each piece, adding warmth, color, and authenticity. Unlike pans with an abundance of exposed copper, these pieces clean easily and are lined with durable food-safe stainless steel.