Product Details: Outfit your semi to be Ready for the Road Ahead™ with superior stopping power in even the most challenging of conditions, with the Bendix R-14 Series 3/4-14" NPT Universal Brake Relay Valve. Thanks to its fast-release design, this replacement brake valve is able to actuate the brakes in the rear of a vehicle to provide enhanced control and safety. Crafted with state-of-the-art technology to offer a smooth braking action that is suitable for both commercial vehicles and semis. FleetPride is your First Click in Heavy Duty®.