This is the swivel mechanism for the high pressure air at the center of my Campbell Hausfeld automatic retracting air hose reel. That hose is crimped directly on the swivel mechanism instead of adding negligible cost with a threaded fitting.
The upshot is that the hose is not replaceable by itself if damaged. And of course parts are not readily available. Throw out the whole thing instead and buy something new. Assholes.
Looks like a banjo fitting. You'll need to know the diameter of the center stud but several companies offer banjo adapters. A good hose shop will be able to make you a replacement hose/fix that hose relatively easy.
You got a hose guy?
I've got a pretty good hose shop in my town. I also know of one where I used to live. You could say I've got hose in different area codes.
Bro, that was amazing.