Its a shame they don't come up with a *standard* like the normal connectors, they all seem to fit each other between brands if the sizes are the same of course!
Many of the manufactuers make this coupler. It's just a matter of making sure it is crossed correctly.
I know Parker makes a compatible coupler, but they also have another one that was used on the Case 1840/45 and some slightly newer model before the joined the Bobcat/Faster style.
I know Princess Auto in Canada had another brand "DNP" that was compatible, and the brand Mark mentions.
The local hose shop guy shook his head a year ago when I showed him one, but he now carries them, apparently because CN railways uses them on something.
Its no longer a matter of what brand, its a matter of knowing what part # it is in the brand thats available. Also there are different threads available for the hose end, such as 1/2" and 3/4" NPT (national pipe thread) and ORB (o ring boss)
They are getting to be more common.
Ken