Yes they are and after I finally got my hands on them, I figured out why. They are heavy; have to be to withstand the pressure, and even heavier filled with 4 to 6 quarts of food. Then you ask a housewife to lift one of those things up and out of the deepwell at the rear position on the cooktop at the end of the cooking period when it is full of food and it is an entirely different operation than using a pressure cooker on top of the range. Even foods that you allow to go through a regular pressure drop have to be lifted out of the well or it would take much longer. Even on top of the range, the cooker is normally moved to a surface unit that is not hot after the cooking is completed. They were made at the height of the popularity of pressure cooking, but were not very popular themselves.
