The body and lid are 100 percent stainless steel. To ensure uniform heating, the bottom has a core of 4.06 mm thick aluminum sandwiched between two sheets of stainless steel. The base always stays flat, never bulges. Stainless steel stays bright, does not pit or corrode, is easy to clean, and extremely hygienic. Can be used safely for light and deep frying and pressure cooking. Suitable for gas, electric, ceramic, halogen, and induction cooktops.