I forget but I bought a fitting off the shelf from my local hydraulics shop. I posted about my pop tester and I think I included the part number for that fitting.
Note: I went to two hydraulic shops. The first had no idea what it was and the second said 'sure, how many would you like?' They had all kinds of them. Take an injector in and they should be able to recognize it.
I will try a search to find my post but for some reason search doesn't work for me on this site.