Ensuring you are Ready for the Road Ahead , the Gates 31309 Heavy Duty Radiator Cap is built to last with its corrosion-resistant, heavy gauge metal. Experience long service life and accurate pressure control, while covering a wide range of pressures. With this precise pressure control, no adjustment is required for installation. This heavy duty radiator cap is designed to raise the radiator fluid’s boiling point in order to prevent premature boiling and overheating in your heavy duty cooling systems, maintaining your active road time. FleetPride is your First Click in Heavy Duty .