Hybrid Racing fuel rails are made from 6061 aluminum with T6 heat treatment and features a durable anodized finish with a laser etched logo ensuring that your engine bay looks fresh and your engine stays fed! Each rail includes a 1/8" NPT hole that allow you to mount a fuel pressure gauge directly to your fuel rail. This puts the fuel pressure gauge in a spot that's easily visible, so you don't have to poke around in the engine bay just to see if you have fuel pressure. All of the ports can accept a -8 ORB fitting in the inlet(s) and outlet allowing you to run either -6 or -8 AN fuel lines. The other detail that should stand out is the option for plugging the side inlet and outlet to allow you to run your fuel line to a centrally located -8 ORB fitting. This is positioned so that the fuel line can pass between the middle two cylinder intake runners (depending on your intake manifold.) This is an excellent option for anyone looking to tuck their wires and lines. What intake manifolds is this rail compatible with? This rail has been shown to mount to the PRB, RBC, and RBB intake manifolds without needing any modifications. Any aftermarket intake manifolds that share the same fuel rail mounting points as the PRB, RBC, or RBB should also accept this rail.