Cooks foods in half the time. These 9qt and 4qt pans can be used 2 ways: one can be turned into a low-pressure, pressure cooker with the addition of the pressure cooker cover and the welded, riveted handles locked into position; or, either pan can be used as a standard cooking pan by adding the "see-thru" glass cover and by not locking the handles. What does low-pressure cooking mean? It is convenient and safe because you can open and close the cover anytime to check what you are cooking or to add ingredients. Limited lifetime warranty. White box.