The Racer X Fabrication Bosch fuel pressure regulator adapter is designed to be used with the popular Bosch fuel pressure regulators. The bosch 3 bar and 4 bar regulators are often used on many of today's modern fuel systems in OEM applications. The Racer X adapter allows the use of the Bosch 3 bar and 4 bar regulator to be directly adapted to any 3/4-16 RH threaded fuel rail or -8AN ORB. The adapter is threaded for a -8AN ORB for the return line and comes with a -6AN to 8AN ORB fitting. The complete assembly is anodized black for corrosion resistance and laser etched with the Racer X logo.