Precise Heat Low Pressure Pressure Cooker cooks foods in half the time. These 2 stainless steel pans 9qt and 4qt can be used 2 ways. Either one can be turned into a low pressure pressure cooker with the addition of the pressure cooker lid and the handles locked into position. Or either pan can be used as a standard cooking pan with the addition of the "see thru" glass cover and not locking the handles. What does low pressure cooking mean It is convenient and safe because you can open and close the lid any time to check what you are cooking or to add ingredients. Lifetime warranty.