This 3 Qt. Double Boiler Insert easily nests in All-Clad sauce pans and casseroles with an 8 inch diameter. It is ideal for preparing items on indirect heat, such as melting chocolates or preparing cream-based desserts and sauces. It can also be used to reheat foods that may change in consistency or flavor when applied to direct heat. Please note that this insert is not an ideal fit for Copper Core sauce pans with an 8 inch diameter. Made of single ply stainless steel, not designed for direct heat.