Flow bench tests have proven that Twin Air filters provide increased airflow while reducing the filters tendency to clog. 154222FR - Twin Air Air Filter For Power Flow Kit - KTM/Husqvarna/Gas Gas SXF/EXC-F 250-450, FC/FE/FX 250-450 2019-2022, MC-F/EC-F/EX-F 2021-2022.