THESE ARE THE OPTIONS FOR REPAIR KITS FOR THE 350AST 2 1/2" ONLY. THE 2 1/2" USES A DIFFERENT CHECK FOR THE #2 CHECK THAN THE 3" AND 4" BUT THE #1 CHECK IS THE SAME FOR 2 1/2", 3" AND 4" . THE CHECK RUBBER KIT IS STILL THE SAME FOR THE 2 1/2", 3" AND 4".