This Radium Engineering master cylinder brace is compatible with the left hand drive (LHD) 2015+ Subaru WRX, 2015+ Subaru WRX STi, and 2014+ Forester XT. The 6061 billet aluminum brace reduces firewall flex for a more positive pedal feel. It mounts to pre-existing threaded holes in the engine bay and requires no permanent vehicle modification.