Arlen Ness Slot Track Inverted Series Air Cleaner Kit For Harley Milwaukee Eight Features: CNC machined from forged billet aluminum Forged billet air filter covers feature exposed design and a CNC inverted top that acts as a velocity stack to help pull in more airflow Forged billet aluminum backing plate features patented Big Sucker hidden breather technology and a radius air inlet for smooth airflow Hidden breathers are O-ringed at the heads and exits at throttle body/carb to create a virtually closed-loop system No external hoses or hardware needed Stainless steel jacketed inverted filters feature an inverted pleated top and 360 of pleated sides to pull in filtered air from every angle Performance filters features a black synthetic filter element wrapped in a stainless steel jacket Filter is water-resistant, eliminating the need for a rain sock