ITEM NAME:Brake Bias Proportioning Valve Pressure Regulator For Brake Adjustment Description: Knob Control Brake Bias Proportioning Adjuster Valve - 1/8" NPT Ports Reduce Pressure Up To 57 Percent Adjustable Between 100 And 1,000 psi Knob Adjustment This brake proportioning valves is adjustable between 100 and 1,000 psi with the twist of a knob. This valve can also reduce pressure up to 57 percent . You can adjust brake bias quickly and easily to compensate for changing track.This valve can also reduce pressure up to57 percent. Each proportioning valve frombillet aluminum and gives it a durable anodized finish. 1 set Proportioning Valve Pressure Regulator. Reduce Pressure Up To 57 Percent.