Spectre's Fuel Pressure Regulator was designed to keep the pressure in the fuel lines of your vehicle consistent. This universal pressure regulator is for use on vehicles with less than 15 PSI fuel pressure and not for use on fuel injected vehicles. With an adjustable pressure range of 5 PSI to 9 PSI, it includes barb fittings for 3/8 inch applications. Designed to perform as good as they look, the Spectre fuel pressure regulator includes a bright plated finish. Spectre s Fuel Pressure Regulator was designed to keep the pressure in the fuel lines of your vehicle consistent. Designed to perform as good as they look; the Spectre fuel pressure regulator includes a bright plated finish.