Only All American Pressure Cooker/Canners feature the exclusive, precision machined Metal-to-Metal sealing system. Positive action clamping locks align the cover to the base forming a steam-tight seal. Because no gasket is involved, the cover is always easily opened and closed. All models feature a precision machined pressure regulator weight for accurate pressure control. Established in 1909, Wisconsin Aluminum Foundry has consistently provided the finest quality aluminum and copper-based alloy castings for a wide variety of industries. Wisconsin Aluminum Foundry takes pride in its Quality, Engineering, Manufacturing, and Service that keeps them well ahead of our competition.