Stainless Steel Brakes adjustable proportioning valve is the quick and easy way to allow you to tweak bias and give you the comfortable feel you're looking for when stopping your street machine. Small and compact makes for easy installation in tight spaces. With a minimum of 100psi to a maximum of 1000psi. This proportioning valve will allow you to reduce up to 57 percent of brake line pressure all with a turn of the adjusting knob.