The OBP Screw-Type Brake Bias Valve allows the driver to precisely dial in brake bias. (Screw-Type bias valves allow more flexibility than detented lever-type valves, but they sacrifice repeatability.) This is a great tool for cars which must run a single master cylinder instead of a bias bar. Install the valve in the rear brake line to reduce the amount of pressure at the rear brakes, reducing rear lockup under heavy braking.
The maximum reduction of output pressure is approximately 60% of the input pressure. The billet aluminum housing has 1/8 NPT female inlet and outlet ports.