Nesting comfortably inside the saucepan, the double boiler provides the perfect space for whisking sauces that can't take direct heat. All-Clad's high-performance double boiler is constructed with a durable stainless steel interior, a pure aluminum core and a hand-polished mirror-finished exterior. Lifetime warranty. All-Clad Stainless Steel 3 Qt. Double Boiler Insert Home - Kitchen Kitchen - Cookware