Product Details: The WABCO 12V 2-Delivery Port Trailer ABS Relay Valve Kit 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 air brake pressure accordingly. As a result, this heavy duty ABS relay valve exceeds OEM performance standards and quality, ensuring superior truck and trailer safety. FleetPride is your First Click in Heavy Duty®.