To select the appropriate fitting, use the picture to determine the part that is needed and then select the correct part from the drop down.
OLD/BILLET XONA ROTOR BEARING HOUSINGS USE 14MM COOLANT FITTINGS!
V1 CAST XONA ROTOR BEARING HOUSINGS USE 10MM COOLANT FITTINGS!
V2 (NEWEST) CAST XONA ROTOR BEARING HOUSINGS USE 14MM COOLANT FITTINGS!
The 10mm is available in -4an and -6an, 14mm is available in -4an or -6an comes with one fitting and one crush washer.
All applicable turbos need two fittings per turbo.