The Hard Anodization process alters & hardens the structure of the cookware surface, making it incredibly abrasion resistant and twice as durable as Stainless Steel. The GSI cookware combines the best attributes of a very hard surface treatment with the quick-even heat transfer of aluminum. The process also seals the aluminum, preventing any direct contact between the core & food. Hard Anodized Cookware allows heat to quickly & evenly spread across the bottom & up the sides of the pot making it one of the best cooking surfaces available.