It is machined from solid billet aluminum. It directly replaces factory rail and accepts factory fuel line connection. Because of special internal design fuel is distributed symmetrically to all cylinders. Large internal bore allows better fuel flow to feed aftermarket fuel injectors. External cooling fins help keep fuel at lower temperature. Rail is designed in such way that it can be used on fuel systems with aftermarket FPR and return line. It can be accomplished with just removing end plugs and replacing them with AN-8 fittings (fittings not supplied). We also provide extra 1/8 NPT port which van be used for fuel pressure gages or NOS. It is available in natural aluminum, red, and black anodized finishes.