This is not your typical Harley-Davidson air cleaner. With its clear plexiglass cover and hidden integrated breather system, this Hi-flow air cleaner was designed to give a clean, simple, & aggressive look, made to stand out in a crowd. Introducing a new Nick Trask innovation, every Assault Charge Hi-flow air cleaner comes with the new Trask snap in velocity stack. This simple interchangeable snap-in velocity stack can be changed quickly and easily to accommodate different sized throttle bodies. Clean and easy to maintain with a rechargeable filter element as well as dyno tested in-house producing 8-10 horsepower gains over the stock OEM air cleaner. Proudly made in the USA.