Agency Power Uncategorized AP-UNI-125 Just a little piece to help out the tuning world, Agency Power has just released this Fuel Pressure Regulator Fitting for aftermarket fuel rails. The fitting is 6061 aluminum with a 0 ring (not shown) for a perfect seal on your Fuel Rail. Input end is 0.625 inch and the output is a 6AN fitting. With this piece you can now supply a aftermarket FPR to your vehicle to alter the fuel pressure as needed. Fuel Pressure Regulator Adaptor AP EVO8/Universal Fuel Rail External FPR Adapter