Product Details: Prepare your semi to be Ready for the Road Ahead™, with the Hadley 3/8" PTC 1500 "Next Gen" Series Height Control Valve that provides a comfortable ride and suspension height. To allow operators to increase or decrease ride height as needed, this replacement valve works to regulate the compressed air levels of a vehicle's suspension. Fashioned with an advanced body to quickly replenish air levels after dumping cargo loads. FleetPride is your First Click in Heavy Duty®.