Pro 5R Media: These filters feature Pro 5R oiled 5-layer progressively finer mesh cotton gauze media for maximum performance. The progressive layering of media allows the filter to flow at high levels even when dirty. Rounded Open Pleats: aFe performance air filters use a rounded, evenly spaced pleat design which produces more usable filter surface area for increased flow and greater dust holding capacity. 100% Polyurethane Construction: To allow multiple cleaning cycles, the top and base are made of 100% pliable polyurethane that does not deteriorate with time or exposure to heat and chemicals. aFe Power OE replacement performance filters have a limited life warranty.