Forged billet aluminum backplate features patented Big Sucker™ hidden vent technology and a curved air intake for smoother airflow Open design forged billet air filter covers with a CNC machined inverted section that acts as an intake trumpet to increase airflow Hidden breathers incorporate O-rings in the cylinder heads and outlets in the throttle body/carburetor to create a virtually closed crankcase ventilation system High performance filters consist of a black synthetic filter element surrounded by a stainless steel frame The inverted filters with a black stainless steel frame consist of a pleated front and a side that is also pleated along its entire circumference to draw in filtered air from any possible angle. Made of CNC machined forged billet aluminum No external tubes or hardware required Made in the U.S.A. NOTE: Exempted by CARB Executive Order D-639-7, Exhibit A only for 01-19 fuel injection models Also for 88-90 models; The breather system is not applicable for these model years.