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.
INSTALLATION INSTRUCTIONS AVAILABLE AT WWW.RADIUMAUTO.COM

Fitment:
2015 Subaru WRX STI Base
2015 Subaru WRX STI Launch Edition
2015 Subaru WRX STI Limited
2016 Subaru WRX STI Base
2016 Subaru WRX STI Limited
2016 Subaru WRX STI Series.HyperBlue
2017 Subaru WRX STI Base
2017 Subaru WRX STI Limited
2018 Subaru WRX STI Base
2018 Subaru WRX STI Limited
2019 Subaru WRX STI Base
2019 Subaru WRX STI Limited
2020 Subaru WRX STI Base
2020 Subaru WRX STI Limited