The Method® is a forged billet aluminum air cleaner that features a sculpted CNC machined design and a clear polycarbonate top that provides a window into the inside of your engine's intake system Hard coated polycarbonate window Patented Design (US Patent: D852,680) Patented backing plate technology (US Patent: US 10,851,741 B1) High performance black pre-oiled air filter CNC machined from forged billet aluminum Integrated Patented oil catch / reservoir Increases horsepower, torque & mileage Eliminates oil blow-bye on M8 engines Finish: Red anodize California Air Resource Board: Executive Order D-639-13