K&N Round Straight Universal Air Filter Features K&N filters are perfect for racing applications who want to add some aesthetics to their classic carbureted engine. Filter has a K&N embossed rubber top with a rubber base. Constructed with a non-woven synthetic filter media it can be cleaned and reused and is covered under K&N's One Year Limited Warranty The filter openings can be stretched up to 1/16 to fit in-between sizes Specifications 3.5 Outside diameter 6 Height 5/8 Flange length 2.5 (64 mm) Flange Inside Diameter Flange Type - Center Rd-0720