The Edelbrock 1728 fuel pressure regulator is machined from high quality aluminum. They are compatible with all grades of gasoline, ethanol, methanol and E85 fuels. Features a black and clear finish with -6 inlet, outlet and return ports. Regulator Pressure (psi): 35-90. Boost/Vacuum Reference Port: Yes. Boost/Vacuum Rise Ratio: 1:1. Regulator Inlet Size: -6 AN. Inlet Attachment: Female straight cut O-ring. Regulator Outlet Size: -6 AN. Outlet Attachment: Female straight cut O-ring. Return Fitting Size: -6 AN. Return Attachment: Female straight cut O-ring. Regulator Finish: Black/Clear anodized. Mounting Bracket Included: Yes.