Very compact, can be hidden in cars that do not allow adjustable proportioning valves. Color reference scale on valve stem allows fast, accurate setting. Installs in rear brake line and allows you to adjust front-to-rear brake bias to prevent rear brake lock-up under heavy braking. Can be used as fuel shut-off valve. Rated to 2000 psi. Flows 3 gpm. Inlet: 1/8" NPT port. Outlet: 1/8" NPT port. Learn more about how adjustable proportioning valves work by reading our tech article. Brake System Selection.