California Classic Chrome Part Number CCC153A Air Cleaner Adapter is Approximately 1/8 Inch Thick Plastic This Air Cleaner Adapter Has A 5 1/8 Air Cleaner Flange And A 2 5/8 Carburetor Flange This Air Cleaner Adapter Is 1/2 Inch Tall And Will Raise Your Air Cleaner Slightly For Customers With Two Barrel Carburetors With A 2 5/8 Air Cleaner Neck Size That Want To Run Any Of Our Air Cleaners, With This Adapter You Can Run "Any" Air Cleaner We Sell On Your 2 5/8 Inch Neck Size Two barrel.