Automatically vents or exhausts air and acts as a visual indication of pressure. Use this air vent on Presto cookers or canners. Fits pressure cookers manufactured before 1977. Including model Nos. 40, 60, 103, 403, 603, 703, 733, 803, 803B, 833, B301A, B301B, B302A, C301A, C301B, 40, 104, 46, 50, 60, 204, 404, 604, 704, 744, 804, 804B, A401, A403A, A403AD, A403AT, A414A, A405A, A407, A409, A410A, A411A, A412A, A415A, A413A, A416A, B401A, B401B, B403A, C401A, C401B, KE02A, PB01A, KE02AT, PB05A, PB07A, SC-35, S-60, 01/PCA4, 01/PCC4, 01/PCC4A, 01/PCD4, 01/PCC4D, 01/PCC4H, 01/PCD4H, 01/PCE4, 01/PCE4A, 01/PCE4H, 01/PCS4, 02/PCS4, 02/PCA4, 02/PCA4H, 40, 106, 206, 406, A601, 706, A603A, A617, A603AD, A614A, A603AT, A608, A618, A605A, A605B, A607, A621A, A609A, A610A, A620A, A611A, A619A, A612, A615, A622, A613, A616, A623, B601A, B602A, B604A, B604B, B604C, B605A, B606B, C601A, C603A, KE03A, PB02A, PB09A, KE03AT, PB06A, PB10A, PB08A, PB11A, S-66, 01/PCA6, 01/PCC6, 01/PCC6A, 01/PCC6AD, 01/PCC6D, 01/PCC6H, 01/PCC6HD, 01/PCE6, 01/PCE6A, 01/PCE6H, 01/PCS6, 02/PCS6, 02/PCA6, 02/PCA6H, and 02/PCE6H. Pressure canners: 7, 7S, 7AV, 14, 7B, CA16, 21, 21S, 21AV, 21B, CA21, 01/CA16H, CA16H, 01/CA21H, CA21H, 01/CAA12H, 01/CAA20H, 02/CAA12H, 02/CAA16H, and 02/CAA20H.