Equip your semi to be Ready for the Road Ahead , with the Tramec 1.5" x 3" Inline 2 psi Quick Release Valve, a crucial device that rapidly releases air brake pressure. By utilizing a sophisticated design, this replacement valve is able to quickly release compressed air from the brake chambers into the brake shoes, allowing vehicles and trailers to stop or slow as needed. Prepared with durable materials to tolerate extreme pressures. FleetPride is your First Click in Heavy Duty .