This device lets you adjust the front to rear braking balance by proportionally decreasing the rear (or in some cases the front too) brake line pressure. Valve only weighs 5.2 ounces and has two side .25" side mounting holes spaced 1.00" apart. 

• Allows easy adjustment of front to rear brake bias
• Universal design works on all race cars
• 100-1500 psi range, up to 57% pressure reduction
• accepts 1/8"-27 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 and thus prevents severe rear brake lockup under moderate-to-heavy braking.

Overall length is 4.25" and overall width is 1.61. 

Note: Universal design. 100 to 1500 psi range, up to 57% pressure reduction. Includes (2) 1/8 NPT to 3/8"-24 IFF fittings.