This filter features 5-layers of progressively Finer Oiled Cotton Gauze and 2-layers of Finer Porosity Synthetic non-woven media for highest filtration efficiency for extreme dust environments. (US PAT 06811588). 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. This pliable sealing surface conforms to even the most uneven filter housing. This design eliminates the use 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. aFe Power performance air filters are constructed using full 360 degree polyurethane frame. This construction allows for a proper factory style fit with excellent filter strength.