All American Canner Pressure Cooker 21.5Qt Silver. Positive action clamping locks align the cover to the base forming a steam-tight seal. At the same time this metal-to-metal seal automatically permits venting under unusual pressure conditions providing an extra margin of safety over conventional rubber or composition gasketed cookers. NOTE: Jar capacities are based on round regular mouth standard Mason jar sizes. Specifications for All American Canner Pressure Cooker: Manufacturer: All American Color: Silver Included Accessories: Standard Quantity: 1 Condition: New Finish: Satin Age Group: Adults Package Contents: All American Canner Pressure Cooker All American 921: Canner Pressure Cooker 21.5Qt Silver