Fuelab 51504-3 - 515 Carb Adjustable FPR 4-12 PSI (2) -6AN in (1) -6AN Return - Blue IXT7_E0FGR64

They accept port style and non-port style union fittings without interference. Several configurations are available, supporting carbureted applications as low as 1 PSID to fuel injected applications up to 125 PSID. The 515 Series Fuel Pressure Regulator has a -6AN return port located on the bottom. The 525 Series has its return port in-line with the inlet port (not on the bottom) which allows for easy installation in extremely tight locations.