Stage 2 Si ProGuard7 Washable/reusable oiled cotton gauze media Maximum performance with highest filtration efficiency 7-layers of progressively finer media aFe ProGuard7 washable/reusable cotton air filters are made from high-quality materials to ensure a tight seal without gaskets or sealant. They're available in a variety of shapes and sizes and outflow any other filter on the market. Since air moving in a straight line flows faster, these filters can actually improve airflow and fuel economy. Pro GUARD 7's patented 7-layer media uses 5 layers of progressive cotton gauze, 2 layers of random porosity, non-woven synthetic fiber, and specially formulated oil to provide the highest filtration efficiency available. You will never need to buy another filter again because aFe Pro GUARD 7 filters can be washed and re-oiled time after time. STAGE 2 Si Horsepower: 11-19 HP gain Torque: 20-40 LB-FT TQ Element: Sealed element: Air filter element is completely enclosed Sound: Quiet Power: Sealed air box minimizes intake noise Style: Molded air box with cover and engineered intake tract Installation: 45-90 minutes: Requires removal of stock air box and intake tract PRIMARY CONCERN PROTECTION - Pro GUARD 7 ofers unparalleled engine protection for the most critical, most expensive engines FILTRATION EFFICIENCY BEST - 99.7% - the greatest level of filtration efficiency and engine protection available on the market TYPICAL VEHICLE DIESEL / OFF-ROAD - Pro GUARD 7 was developed specifically for today's demanding diesel applications. Pro GUARD 7 provides the increased airflow and maximum protection your expensive diesel engine needs. DRIVING CONDITIONS EXTREME / VERY DUSTY - Pro GUARD 7 is perfect for all driving conditions, but excels in the harshest, most extreme conditions imaginable