Compact and lightweight forged billet aluminum construction has made Wilwood's proportioning valves the best available. Pressure adjustments range from 100-1000 PSI and provide for a maximum decrease of 57% in line pressure. This adjustment lets you fine tune the front to rear braking balance by proportionately decreasing the rear (or in some cases the front) brake line pressure. Used for street rods, pro series racing and off road vehicles. Can also be used to adjust individual front wheel braking in dirt track applications.