Calphalon Contemporary Stainless Steel Cookware, Sauce Pan and Double Boiler Insert, 2 1/2-quart A heavy-gauge aluminum core is sandwiched between two layers of stainless steel by means of high-heat, high-pressure impact bonding for extreme durability. Aluminum core provides superior conductivity and even heating for excellent browning and control of the cooking process. Non-porous stainless steel cooking surface is safe for use with all utensils. Clear tempered-glass lids let you see food while it's cooking and are oven safe, so you can finish covered dishes in the oven or keep them warm until ready to serve Long, brushed stainless steel handles stay cool on the stovetop. All cookware is dishwasher-safe and carries Calphalon's full lifetime warranty. Stainless Double Boiler Insert Dishwasher Safe Full aluminum core that is sandwiched between the stainless steel interior and exterior of each pan, provides superb conductivity and even heating throughout the vessel Lifetime Warranty Lifetime Warranty