The Calphalon AccuCore Stainless Steel line of cookware is the absolute culmination of every innovation in stainless steel cooking. Each pan consists of 5 metal layers that are fashioned from 3 different heavy-gauge metals. The accelerated heating and cooling capabilities of the pure copper core allows for superior temperature control. There are 2 layers of aluminum encasing the copper core ensure equal distribution of heat. The final 2 layers of stainless steel provide a professionally versatile cooking surface. The AccuCore Stainless Steel 16" Roaster with Rack is the best investment you can make in skillful cookware.