This set is, essentially, three small based air cleaners from the small center carb of the 57 / 58 to the two smaller outer carbs. Show Quality, mirror chrome. Excellent reproduction. Included in sets ,three bases, three paper elements, three chrome lids, three correct air cleaner gaskets. Chrome wing nuts are available on the web site for set of three $5.50 or wing nuts and air cleaner studs for $12.50. NO disappointments. Also fits 348 tri-powers and Olds J-2