aFe 72-90037 Pro Guard 7 Air Filter Improves airflow for better performance and acceleration Pre-oiled, washable/reuseable air filter for long service life with life-time warranty Patented Pro-GUARD 7 Five-Layer Progressively finer mesh cotton media with Two-layer Progressively finer porosity synthetic media for highest filtration efficiency for extreme dust environments. Tall, Rounded, evenly-spaced pleats for maximum dust holding capacity Constructed with 100% pliable polyurethane for great seal without the use of foam gaskets or sealing grease.