Equip your semi to be Ready for the Road Ahead , with the Haldex 2S / 1M FFABS Valve Kit, a crucial kit to control the flow of compressed air in the anti-lock brake system. After the brake pedal is pressed, multiple components such as this valve work together to transfer compressed air into the anti-lock brake system. Built with a durable body to tolerate extreme pressures and demanding operating conditions. FleetPride is your First Click in Heavy Duty .