Keeping Expertise Built In , the OTR 2-Port Relay Valve is a critical component, ensuring you apply or release your rear air brakes in a fast, safe manner. This OTR relay valve is compact yet powerful and eliminates brake lag. This 2-port relay valve weighs approximately 1.5 lbs with two mounting holes,.34” diameter on 1.50" centers. It also has a cracking pressure of 5.6 +/- 1.0 psi. In addition, this OTR relay valve's innovative design and composition ensure consistent and quick braking at safe distances. In the end, this heavy duty service relay valve is strong, efficient, and long-lasting for your truck and trailer. FleetPride is your First Click in Heavy Duty.