Description Unique Quantum Filter Design:The Quantum uses an integrated filter-to-housing design (patent pending) by attaching the filter to the housing with 4 captive screws for a positive surface area seal and quick and easy install. Quantum Pro 5R Filter Media:The Quantum Pro 5R filter is our oiled, 360-degree radial flow air filter with 5-layers of progressive cotton composite media that provides maximum flow, performance and protection. Recommended for normal, everyday street and performance driving. Quantum Pro DRY S Filter Media:The Pro DRY S is our oil-free, 360-degree radial flow air filter with 3-layers of progressive synthetic media provides optimum flow, protection and cleaning convenience. Recommended for normal to dry, dusty driving conditions. Patented Pro-GUARD 7 Filter Media:This filter features Pro-GUARD 7 media that consists of 5-Layers of progressively finer mesh oiled cotton gauze and 2-layers of finer porosity synthetic non-woven media for maximum protection in the most extreme environment. The Pro-GUARD 7 filter media has been tested at 99.51 percent filtration efficiency. Note:The Quantum Pro-GUARD 7 filter is specifically designed for Quantum Cold Air Intake Systems.