This Hawkins Pressure Cooker body and lid are 100 percent Stainless-Steel. To ensure uniform heating, the bottom has a core of 4.06-millimeter-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. It can be used safely for light and deep frying and pressure cooking