Each piece is constructed of extra heavy surgical stainless steel and guaranteed to last a lifetime. The 7-ply construction spreads the heat quickly and evenly. The steam control valve makes "waterless" cooking easy and more healthy because it eliminates the need for grease or oil in cooking. To use the steam control valve, start cooking on medium heat (never use high heat) then, when the valve begins to whistle, close the valve and turn the heat down to low and finish cooking. The 7-ply construction allows you to stack cook with this cookware. Begin cooking on individual burners and when the valve whistles, you can stack the pans to finish cooking. The phenolic handles are superbly styled and are resistant to heat, cold and detergents. Comes with a limited lifetime warranty. Before you invest up to $2000 in a set of 7-ply cookware, consider our advantages and superior features. Gift boxed.