Prepare your semi truck to be Ready for the Road Ahead™, with the Watson & Chalin 12V Hi Flow Lift Axle Control Valve that adjusts the height of a vehicle's axle. Due to its sophisticated design, this replacement component is able to control the height of a vehicle's axle to optimize its suspension performance. Engineered with a pressure-resistant design to withstand wear and tear from everyday use. FleetPride is your First Click in Heavy Duty®.