PROTECT YOUR INVESTMENT - The IAG AOS maintains OEM PCV system functionality, but supplements its capacity. The design is based on years of extensive testing on standard and competition applications. The large, 1-liter, cast aluminum swirl pot canister more effectively separates oil from the PCV system upstream of PCV gasses' return to the intake system. The AOS' fully-heated cast aluminum housing, superior venting, and unique baffle design set it apart from the rest.