Fig. 1 - (M16xP1.5 O-ring type to Nismo-type adjustable fuel pressure regulator for older-type GReddy Fuel Rails with M16xP1.5 O-ring fittings)

Fuel regulator union (for previous generation GReddy fuel delivery tube)

This is an adapter for attaching a genuine fuel regulator or an external fuel regulator to the GReddy delivery tube.

Fuel delivery tube adapter

M16-Flexible regulator flange ● Machined aluminum, O-ring included
Adapter for attaching a Nissan type fuel regulator to the GReddy delivery tube.