K&N replacement air filters are washable and reusable and provide high air-flow with excellent filtration. Features: Engineered to provide increased horsepower and acceleration Designed for quick foam or filter servicing after initial install Specifically designed with special media and dry foam insert for maximum off-road protection Developed to run without the foam for increased track performance or with the foam for a boost in filter endurance on the trails Fits directly into the OEM airbox with application-specific sealing ensuring a precise fit Unoiled foam pre-filter is easy to clean and re-use Filter element is pre-oiled and ready to ride Specifications: Filter Material: Cotton Gauze Height: 37mm Outside Length: 195mm Outside Width: 189mm Weight: 0.4kg Filter Re-Oiling Amount: 24ml Fits: Yamaha WR450F 2019-2021 WR450FSP 2021 YZ250F 2019-2021 YZ450F 2018-2021 YZ450FSP 2021 YZ450FX 2019-2021