Product Details: The Haldex Remanufactured Trailer Spring Brake Relay Valve is designed to provide reliable and efficient control of the parking and emergency brake functions on trailers. This valve is rigorously tested to guarantee dependability and great efficiency. This valve is created for trouble-free air brake system maintenance and repair, and is the perfect choice for any trailer. With this Relay Valve, you can be sure that your trailer's brakes will be working properly and safely. FleetPride is your First Click in Heavy Duty®.