Equip your semi to be Ready for the Road Ahead , with the MGM Brakes Piston Long Stroke Spring Combination Service Brake Chamber, a key piece that offers fast and responsive brake pressure. By utilizing a specialized design, this replacement brake chamber is able to react to pressure from the brake pedal by expanding outward, and allowing the pushrod to activate the brakes. Built with solid materials to provide an extensive service life. FleetPride is your First Click in Heavy Duty .