Need help on a tank set up

can someone please either post up a pic or a link of the type of fill connector and whip, pressure gage and bleed screw, of what goes into a fire fighters tank? I’m familiar with a DIN connector like what’s on my AirHog, but unsure of what to get for my hand me down fire tank. I’ve tried doing the research, but have trouble even zooming in to see pics of fill stations. Thank you for sure
 
Here is what I am using about a $40 bill.



https://www.ebay.com/sch/i.html?_nkw=airgun%20fill%20347&ssPageName=GSTL

s-l225.webp