These anodized billet aluminum adapter fittings can be used in any application using a 5/16"-24 O-ring port. This is the same thread pitch used in -2AN (ORB=O-Ring Boss). They all feature FKM O-rings for all oil and fuel types.
This would be used if the external quick fill DSV needs to be remotely mounted off the fuel cell. It will secure directly into the 12AN ORB Vent Port on the Radium FCST.