This Radium Engineering master cylinder brace is compatible with the left hand drive (LHD) 2015+ Subaru WRX, 2015+ Subaru WRX STi, and 14-18 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. Because the master cylinder flexes in an accurate path, a specially designed CNC machined foot contacts the master cylinder to counteract the arc movement. Preload is adjustable, and installation is simple and takes less than 30 minutes.