Allstar Brake Bias Gauges show actual front and rear line pressure for making brake bias changes before or during the race. Pre-assembled units have 0-1500psi liquid filled gauges with 1/8″NPT male fittings and bleeder valves to evacuate air from the gauges. 2-3/4″ x 4-1/2″ pre-drilled panels are offered in horizontal or vertical versions.