Honestly , I have no idea what happened . Maybe the oring was already too big for it and I didn ' t realize before throwing the lid in the sanitizer jar . The oring looks exactly like this one on this picture 375373 dtel I think it ' s just too big for the lid , either way without the oring it seems to be sealing ok , at least I get movement in the airlock when I press the sides of the fermonster . Edit and yes , it was a long fucking day ! but I got 15 Gallons fermenting and a couple racks of ribs cooked p <| sep |> Thanks ! I try to make it that way Lol . <| sep |> We don ' t need to change the system . It works just fine . It fact , it worked just like it was supposed to . Again Trump ran a better campaign . End of discussion .