Pro DRY S Media: This filter features 3-layers of progressive media to provide maximum flow with excellent filtration. The progressive layering of media allows the filter to flow at high levels even when dirty. The Pro DRY S non-oiled synthetic air filter requires no oils for cleaning for maximum convenience. 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. Progressive Bump Seal: This pliable sealing surface conforms to even the most uneven filter housing. This design eliminates the us e of gaskets or sealants. The soft urethane construction always goes back to its original form so you will never compress the bump seal. This makes for a perfect filter fit and sealing surface every time. Full Urethane Housing: aFe Power performance air filters are constructed using full 360 degree urethane frames. This construction allows for a proper factory style fit with excellent filter strength. aFe Power factory replacement performance filters have a limited lifetime warranty.