All EJ20 / EJ25 engines. For Subaru WRX 2002-2014. For Subaru STI 2004-2020. Type: Coolant Mod Kit. For Subaru Forester XT 2004-2008. For Subaru Legacy GT 2005-2009. --This kit balances the coolant flow by diverting it from the head to the heater core lines, reducing knock and ringland failure risks.
