K&N Performance Replacement Elements simply drop into the original air box, replacing the original restrictive paper air filter with a performance, high flow element. No other modifications, parts or accessories are required.The pleated cotton and mesh gauze filters have been designed to improve air flow and horsepower, offering a crisper throttle response and superior performance for improved acceleration and greater driving enjoyment. All this with the highest level of filtration (up to 5 times greater than non pleated designs), giving the ultimate protection for the engine.K&N replacement elements are supplied pre-oiled and ready to use, and can be used over and over again. Simply clean and re-oil the element with the K&N service kits (available to purchase separately) for long lasting performance gains and up to 50,000 miles between air filter cleaning. Not having to buy another air filter means the K&N filter is also environmentally friendly! The K&N Million Mile Limited Warranty