This fuel pressure gauge adapter fitting will allow you to mount a fuel pressure gauge to your fuel pressure service port on your Jeep 4.0 fuel rail. Simply bleed the fuel pressure from your fuel rail, remove the core from your schrader valve and screw on this fitting. You can then install the Fluid Flow Performance fuel pressure gauge and monitor fuel pressure at all times. 
 
This fitting will fit all Jeep 4.0 fuel rails that are equiped with a schrader valve service port.