These fuel pressure regulators are machined from aircraft quality aluminum for those who demand the best. These carbureted fuel pressure regulators have an internal diaphragm made of fluorosilicone to ensure high temperature protection resulting in an extended life. They are compatible with all grades of gasoline, ethanol, methanol and E85 fuels. Select regulators available with 1/8" NPT gauge port and a boost reference fitting for blow through or pressurized carburetor applications (even beyond 30 psi of boost). Pressure regulation slope is 0. 75 psi/gal of flow rate change. Will hold fuel system pressure for at least 20 minutes after pump shutdown. Developed for optimum compatibility with Edelbrock electric fuel pumps.