The Radium air/oil separator traps blow-by oil before it can be sent back to the induction system. The collected oil is heated by the AOS to remove moisture, then allowed to drain back into the engine block, making this a zero maintenance system. Installation is done using factory mounting points. All required hardware, hoses and other items are included in the kit.

This Part Fits:

Year	Make	Model	Submodel
2015-2020	Subaru	WRX STI	Base
2015	Subaru	WRX STI	Launch Edition
2015-2020	Subaru	WRX STI	Limited
2016	Subaru	WRX STI	Series.HyperBlue
2018	Subaru	WRX STI	Type RA