aFe Power 42-12032 DFS780 Series Diesel Fuel System (Non-CARB Compliant) Supplied preset boost switch activates pump only under load, reducing wear & tear on both the DFS780 and the stock high-pressure pump Clear high-impact polycarbonate sight glass for visual inspection of fuel Helical Spur Gears runs quieter than straight cut gears Contoured CNC manifold enhances flow This product is not CARB exempt at this time and is not legal for sale in California or use on vehicles registered with the California Department of Motor Vehicles