It comes with everything to install it on factory lines. here is a little description

AEM High Volume fuel rails feature a 1/2-inch fuel bore to support fuel flow for applications up to 1,000 horsepower. This large bore also dampens backpressure pulses created by larger injectors and works perfectly with stock injector sizes. An additional 1/8th NPT port is included to accommodate a nitrous set up or fuel pressure gauge. A custom fuel line fitting is included for the factory fuel line, and the ends of each rail are pre tapped to accept -6 AN or 9/16”x18 fittings for users who want to use custom fuel lines.

- No additional parts required for installation
- Specifically engineered for each application
- Manufactured and assembled in the USA
- O.E. fuel pressure regulator or AEM adjustable fuel pressure regulator mounts directly to rail with no modifications
- Comprehensive installation instructions, hardware, fittings and injector O-rings included