Forged billet aluminum air cleaner featuring a polycarbonate window to view the internal working of the air intake system, Polycarbonate is hard-coated for long lasting durability and protection from engine oil and UV sunlight , Radius air inlet provides unobstructed airflow into engine, Includes backing plate, forged filter housing, clear polycarbonate top, filter, gaskets and necessary hardware, Each hidden breather is o-ringed at the heads, passes through the backing plate and exits inside the mouth of the throttle body through proprietary shooter tubes. This eliminates the need for any external hoses or hardware for a virtually closed loop system , High-performance filter is constructed from black pre-oiled cotton for optimum flow and filtration