1951 1952 1953 1954 1955 1956 Cadillac Oil Bath Air Cleaner Original Some mistakenly refer to this as a Bat Wing Air Cleaner The Bat Wing was for two 4 bbl carbs This is an original oil bath (not paper) air cleaner for a single 4 bbl carb The carb opening measures 4 3/8" If you are doing a correct restoration, this is the air cleaner you need.