The All American 21.5 qt (20.3 L) pressure cooker/canner offers the best and safest method for heavy-duty home canning. A pressure cooker works by trapping steam, which builds pressure and drives the boiling point of water. Therefore, the higher temperature shortens cooking times and extracts more flavour from foods. The elite All American line of heavy-duty pressure cookers offers the best and safest method for home canning. For almost one hundred years, All American has been crafting robust, heavy-duty, and heavy gauge cast aluminum stovetop pressure canners for use with meat, fish, poultry, and vegetables. Only All American Pressure Canners feature an 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. Note: ensure you read the manual before use and follow all guidelines accordingly.