Holley Billet 2 Port Adjustable Fuel Pressure Reg Carbureted 4.5-9PSI # HO12-840Holley Billet 2 Port Adjustable Fuel Pressure Reg Carbureted 4. 5 9PSI # HO12 840 Fuel Pressure Regulator, HP Billet, 4 1 2 to 9 psi., Female 3 8 in. NPT Inlet Two Outlets, Black Clear Pressure Range (psi): 4. 5 9 Regulator Style: Non return Regulator Location: Inline Boost Vacuum Reference Port: No Gauge Port: Yes Inlet Quantity: One Inlet Size: 3 8 in. NPT Inlet Attachment: Female threads Outlet Quantity: Two Outlet Size: 3 8 in. NPT Outlet