Product Details: The Bendix QR-1 Series 1/2-14" NPT Supply Port Air Brake Quick Release Valve is a reliable and durable solution for controlling air pressure in your vehicle's braking system. This valve is often mounted on the axle and serves two spring brake actuators. It is made of high quality materials for an extended lifespan and delivers within 1 psi of control pressure to the controlled device in the standard configuration. It also comes with optional noise reducing foam crossers or silencers for a quieter operation. This valve is a great choice for any vehicle that needs reliable and efficient air brake control. FleetPride is your First Click in Heavy Duty®.