Product Details: Update your semi with fast and reactive rear air brakes, with the Bendix ATR-6® 5.5 psi Antilock Traction Relay Valve that ensures you're Ready for the Road Ahead™. This replacement component allows for the immediate application of compressed air to the rear air brakes, by acting as a gateway between the service reservoir and the brakes. Engineered with a durable metal body to withstand extreme pressures and consistent use. FleetPride is your First Click in Heavy Duty®.