Twin Air filters are slightly smaller than stock filters to increase air space around the filter and improve circulation. The resulting increase in air volume around the filter improves circulation within the airbox. More air means more power for your engine. Flow bench tests have proven that Twin Air filters provide increased airflow while reducing the filters tendency to clog. Features • Coarse open-pore foam catches airborne dirt, grime and sand • Fine open-pore inner foam acts as a second filter to trap the smallest particles while ensuring maximum air passage • Exclusively formulated adhesive withstands repeated cleanings, even with harsh solvents or gasoline • Thick, flat foam, greaseless sealing ring ensures maximum contact with your airbox, while acting as a breathable gasket for increased air passage • Fused outer and inner elements prevent dirt and grime from being lodged between layers AIR FILTER FANTIC XE125 21-23 XX125 21-23 XX250 21-23 YAMAHA YZ125 97-25 YZ250 97-25 YZ125X 20-25 YZ250X 16-25 YZ250F 01-13 YZ450F 03-09 WR250F 01-02 YZF/WRF400-426 98-02