We collaborated with the legendary coppersmiths at Ruffoni to create our exclusive Thermo-Clad™ Copper series. Designed to bring the joys of cooking with premium copper to home cooks, the bonded pans combine beautiful mirror-finish copper with the practical maintenance of stainless steel. This cookware set offers maximum heat responsiveness on the stovetop, giving you more control for every task from sautéing and simmering to braising and stir-frying. Four-piece set includes 10" and 12" fry pans and 4 1/2-qt. covered sauté pan. Thermo-Clad technology bonds thick, mirror-polished copper to a thin interior layer of 18/10 stainless steel. Made from 1.2mm-gauge copper. Solid copper is the fastest heat conductor, ensuring quick, efficient and uniform heating with precise temperature control. Stainless-steel lining is nonreactive and ensures ease of use and maintenance for a lifetime. Ergonomic stainless-steel handle provides comfortable grip and maximum control. Double-wall insulated stainless-steel lids keep food warm. Oven safe to 450°F. Handcrafted in Italy by Ruffoni exclusively for Williams Sonoma.