Allows easy adjustment of front to rear brake bias. Universal design works on all race cars. 100 to 1500 psi range, up to 57% pressure reduction. Uses 1/8" NPT fittings.
Compensates for weight transfer to the front wheels during braking. All factory brake systems allow for this in some fashion. An APV allows you to "fine tune" a street or race brake system (which normally uses components from a variety of sources) and thus prevents severe rear brake lockup under moderate-to-heavy braking.