What fill adapter for Sperian 30 min 4500 psi

[Pantanni]

Hi. I just got a used Sperian 4500psi 30min air tank and I need whatever is used (fill adapter?) to hook up the bottle to fill my Hatsan Flashpup. Can anyone point me in the right direction? I'm trying to ensure i get the right valve and fill hose.

Thanks

 

[Pantanni]

I think I just discovered that this tank is beyond its 15yr life but the friend who gave it to me is looking for one with a little more life left. Still interested in what fill valve to use.