FWF HONDA CRF 250R AIR FILTERDouble the surface area, Twice as effective. To accommodate the 2021 CRF 450Rs updated air box design, FWF designed this filter with a flat panel design to create a more secure seal and stronger structure for the filter to further ensure no dust can penetrate the airbox. The Flat Panel Design: Compact design allows more volume in the air box Any dust is distributed evenly over the pyramid profile outer foam surface Dual foam layer construction