Product Details: Prepare your semi truck to be Ready for the Road Ahead™, with the Power Products TR-3 Type 40 psi Inversion Valve that provides enhanced control of pneumatic accessories. This replacement valve regulates the flow of compressed air, switching the direction of the flow between two ports as needed. Manufactured with top-quality materials to provide a smooth and energy-friendly operation. FleetPride is your First Click in Heavy Duty®.