Used on cookers and canners built prior to 1977. Allows excess steam to escape. Compatible Products 01/CA16A - 16-Quart Pressure Canner 01/CA16H - 16-Quart Pressure Canner 01/CA21A - 21-Quart Pressure Canner 01/CA21H - 21-Quart Pressure Canner 01/CAA12H - 12-Quart Pressure Canner 01/CAA20H - 20-Quart Pressure Canner 01/PCA4 - 4-Quart Aluminum Pressure Cooker 01/PCA6 - 6-Quart Aluminum Pressure Cooker 01/PCC4 - 4-Quart Cast Aluminum Pressure Cooker 01/PCC4A - 4-Quart Cast Aluminum Pressure Cooker 01/PCC4D - 4-Quart Cast Aluminum Pressure Cooker 01/PCC4H - 4-Quart Cast Aluminum Pressure Cooker 01/PCC6 - 6-Quart Cast Aluminum Pressure Cooker 01/PCC6A - 6-Quart Cast Aluminum Pressure Cooker 01/PCC6AD - 6-Quart Pressure Cooker 01/PCC6D - 6-Quart Pressure Cooker 01/PCC6H - 6-Quart Cast Aluminum Pressure Cooker 01/PCC6HD - 6-Quart Pressure Cooker 01/PCD4 - 4-Quart Pressure Cooker 01/PCD4H - 4-Quart Pressure Cooker 01/PCE4 - 4-Quart Pressure Cooker 01/PCE4A - 4-Quart Pressure Cooker 01/PCE4H - 4-Quart Pressure Cooker 01/PCE6 - 6-Quart Pressure Cooker 01/PCE6A - 6-Quart Pressure Cooker 01/PCE6H - 6-Quart Pressure Cooker 01/PCS4 - 4-Quart Stainless Steel Pressure Cooker 01/PCS6 - 6-Quart Stainless Steel Pressure Cooker 02/CAA12H - 12-Quart Pressure Canner 02/CAA16H - 16-Quart Pressure Canner 02/CAA20H - 20-Quart Pressure Canner 02/PCA4 - 4-Quart Alumium Pressure Cooker 02/PCA4H - 4-Quart Pressure Cooker 02/PCA6 - 6-Quart Alumium Pressure Cooker 02/PCA6H - 6-Quart Pressure Cooker 02/PCE6H - 6-Quart Pressure Cooker 02/PCS4 - 4-Quart Stainless Steel Pressure Cooker 02/PCS6 - 6-Quart Stainless Steel Pressure Cooker 103 - 3-Quart Pressure Cooker 104 - 4-Quart Pressure Cooker 106 - 6-Quart Pressure Cooker 204 - 4-Quart Pressure Cooker 206 - 6-Quart Pressure Cooker 21 - 21-quart Pressure Canner 21AV - 21-quart Pressure Canner 21B - 21-Quart Pressure Canner 21S - 21-quart Pressure Canner 40 (2.5qt) - 2.5 Quart Pressure Cooker 40 (4 qt) - 4-Quart Pressure Cooker 40 (6 qt) - 6-Quart Pressure Cooker 403 - 3-quart Pressure Cooker 404 - 4-quart Pressure Cooker 406 - 6-quart Pressure Cooker 50 - 4-quart Pressure Cooker 60 (4-qt) - 4-quart Pressure Cooker 60(2.5 qt) - 2.5-quart Pressure Cooker 603 - 3-quart Pressure Cooker 604 - 4-quart Pressure Cooker 7 - 16-quart Pressure Canner 700 (3 qt) - 3-quart Pressure Cooker 700 (4 qt) - 4-quart Pressure Cooker 700 (6 qt) - 6-quart Pressure Cooker 703 - 3-quart Pressure Cooker 704 - 4-quart Pressure Cooker 706 - 6-quart Pressure Cooker 733 - 3-quart Pressure Cooker 744 - 4-quart Pressure Cooker 7AV - 16-quart Pressure Canner 7B - 16-Quart Pressure Canner 7S - 16-quart Pressure Canner 803B - 3-quart Pressure Cooker 804 - 4-quart Pressure Cooker 804B - 4-quart Pressure Cooker 833 - 3-quart Pressure Cooker A401A - 4-quart Pressure Cooker A403A - 4-quart Pressure Cooker A403AD - 4-quart Pressure Cooker A403AT - 4-quart Pressure Cooker A409 - 4-quart Pressure Cooker A410A - 4-quart Pressure Cooker A411A - 4-quart Pressure Cooker A412A - 4-quart Pressure Cooker A413A - 4-quart Pressure Cooker A414A - 4-quart Pressure Cooker A415A - 4-quart Pressure Cooker A416A - 4-quart Pressure Cooker A601 - 6-quart Pressure Cooker A603A - 6-quart Pressure Cooker A603AD - 6-quart Pressure Cooker A603AT - 6-quart Pressure Cooker A607A - 6-quart Pressure Cooker A608A - 6-quart Pressure Cooker A609A - 6-quart Pressure Cooker A610A - 6-quart Pressure Cooker A611A - 6-quart Pressure Cooker A612A - 6-quart Pressure Cooker A613A - 6-quart Pressure Cooker A614A - 6-quart Pressure Cooker A615A - 6-quart Pressure Cooker A616A - 6-quart Pressure Cooker A617A - 6-quart Pressure Cooker A618A - 6-quart Pressure Cooker A619A - 6-quart Pressure Cooker A620A - 6-quart Pressure Cooker A621A - 6-quart Pressure Cooker A622A - 6-quart Pressure Cooker A623A - 6-quart Pressure Cooker B301A - 3-quart Pressure Cooker B301B - 3-quart Pressure Cooker B302A - 3-quart Pressure Cooker B401A - 4-Quart Pressure Cooker B401B - 4-Quart Pressure Cooker B403A - 4-Quart Pressure Cooker B601A - 6-Quart Pressure Cooker B602A - 6-Quart Pressure Cooker B604A - 6-Quart Pressure Cooker B605A - 6-quart Pressure Cooker C301A - 3-quart Pressure Cooker C301B - 3-quart Pressure Cooker C401A - 4-quart Pressure Cooker C401B - 4-quart Pressure Cooker C601A - 6-quart Pressure Cooker C603A - 6-quart Pressure Cooker CA16 - 16-quart Pressure Canner CA16H - 16-quart Pressure Canner CA21 - 21-quart Pressure Canner CA21H - 21-quart Pressure Canner KE02A - 4-quart Pressure Cooker KE02AT - 4-quart Pressure Cooker KE03A - 6-quart Pressure Cooker KE03AT - 6-quart Pressure Cooker PB01A - 4-quart Pressure Cooker PB02A - 6-quart Pressure Cooker PB05A - 4-quart Pressure Cooker PB06A - 6-quart Pressure Cooker PB07A - 4-quart Pressure Cooker PB08A - 6-Quart Pressure Cooker PB09A - 6-Quart Pressure Cooker PB10A - 6-Quart Pressure Cooker PB11A - 6-Quart Pressure Cooker S-60 - 4-Quart Pressure Cooker S-66 - 6-Quart Pressure Cooker SC-35 - 4-Quart Pressure Cooker