This K&N air filter is great for people who own racing vehicles, radio - controlled cars, generators, snowmobiles, and tractors. It can be used in various applications where clean air intake is needed. The filter has a round tapered shape, with a 6 - inch outer diameter at the base, a 4.5 - inch outer diameter at the top, and a height of 7 inches. It's easy to install thanks to its flexible rubber flanges and can be reused after washing, making it a cost - effective choice for you.