I worked around two different military bases, 29 Palms MCB and George AFB and learned about the AN hose from them, BTW AN stands for Army Navy specifications.
In today's world of counterfeit parts imported and sold here in the U.S. as meeting the AN standard we all know that ain't so now whiney
I have bought a bunch of new and new surplus AN fittings and hoses, some of the new currently sold hoses are NOT built to the AN specs down rant whiney
Be careful on what you buy, DO NOT buy the cheapest available when it comes to hoses that can hurt you when they fail tsk work

Mr.Cab Racing and winning with Mopars since 1964. (Old F--t, Huh)