The Bendix TW-4 2-Position Self-Return Type Air Brake Control Valve is designed to provide reliable operation even under extreme conditions. It is a manually operated momentary non-modulating control valve that is commonly used in conjunction with air starter systems. It is engineered using state-of-the-art technology to meet your vehicle's more stringent compressed air requirements. Its robust construction and reliable performance make it the perfect choice for your truck's air brake system. FleetPride is your First Click in Heavy Duty .