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. 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 a comfortable grip and maximum control. Double-wall insulated stainless-steel lid keeps food warm. Oven safe to 450°F. Handcrafted in Italy by Ruffoni exclusively for Williams Sonoma. 10-Piece Set includes: 10" and 12" fry pans 1 1/2-qt. and 4-qt. saucepans with lids 4 1/2-qt. sauté pan with lid 8-qt. stock pot with lid