The WABCO 12V 4-Delivery Port Trailer ABS Relay Valve keeps you Ready for the Road Ahead™ providing safe, reliable control over the application and release of parking and service brakes. This WABCO relay valve utilizes wheel speed sensors to properly detect when a wheel will lock up and automatically intervenes to adjust brake pressure accordingly. As a result, this heavy duty ABS relay valve exceeds OEM performance standards and quality, ensuring superior vehicle safety. FleetPride is your First Click in Heavy Duty®.