This filter features three layers of oil-free synthetic media and requires no oil during maintenance to provide maximum convenience. Its progressive layering provides great filtration efficiency and dust holding capacity. This media is best suited for street use. Pro DRY S filters are easily recharged with aFe's POWER CLEANER. The lightweight tubes are computer-designed to achieve maximum power gains while maintaining a perfect fit. Manufactured from 100% twill weave carbon fiber, they feature zero fiberglass and are clear-coated for the highest quality construction. Stainless-steel clamps and silicone couplings are used for strength and durability.