Holley Dominator Billet Fuel Pressure Regulator 4.5 - 9 PSI # HO12-847Holley Dominator Billet Fuel Pressure Regulator 4. 5 9 PSI # HO12 847 Fuel Pressure Regulator, Inline, 4. 5 9 psi Pressure Range, 10 AN O ring Female Threads Inlet Outlet, Each Pressure Range (psi): 4. 5 9 Regulator Style: Return Regulator Location: Inline Boost Vacuum Reference Port: No Gauge Port: Yes Mounting Bracket Included: Yes Fittings Included: No Rebuildable: No Inlet Quantity: One Inlet Attachment: Female threads Inlet Size: 10 AN O ring