K&N Filter Universal Rubber Round Straight Filter 20 Deg Angled 2-7/16in Flange 3-3/4in OD 4in HK&N's Universal Air Filters are designed and manufactured for a wide variety of applications including racing vehicles, radio controlled cars, generators, snowmobiles, tractors, and other applications. Regardless of the angle or offset diameter of the air intake, there is probably a K&N Universal air filter for your equipment. All filters are constructed with ultra strong molded pliable rubber flanges which absorb vibration and allow for secure