Forged billet aluminum backing plate features Big Sucker hidden breather technology and a radius air inlet for smooth airflow. Forged billet air filter covers feature exposed design and a CNC inverted top that acts as a velocity stack to help pull in more air flow. Hidden breathers are O-ringed at the heads and exits at throttle body/carb to create a virtually closed-loop system. Performance filters features a black synthetic filter element wrapped in a stainless steel jacket. Black stainless steel jacketed inverted filters feature an inverted pleated top and 360 of pleated sides to pull in filtered air from every angle. CNC-machined from forged billet aluminum. No external hoses or hardware needed. Made in the USA.