Prepare your semi to be Ready for the Road Ahead , with the Prima Brake 3-Way Solenoid Air Valve that provides advanced control of fluid movement and timing. By utilizing a specialized design, this replacement valve is able to automatically manage the flow of fluids in the pneumatic system by either purging excess amounts or allowing more in. Built with reactive electric components to offer a rapid response time and increased reliability. FleetPride is your First Click in Heavy Duty .