Engineered to serve the motocross and ATV industryMade for great performance in the off-road conditionsExpected to provide maximum durability and protectionWill meet and surpass all your filtering needs Universal Air Filter by Twin Air®. This is where it all began. Over 40 years ago, the sandy, gritty soil of The Netherlands - and the resulting engine failures - proved that single-foam and paper filters gave riders air flow, but failed at protection. The fused layers of open-pore foam and fine inner foam trap even the smallest particles. The new, rounder design boosts airflow. So do the minimized seams made possible by a revolutionary micro-gluing process: Shorter seams = more foam = more flow.