Sure, but I can't mail them, and I can only fill to 9000 psi.

IIRC European SCUBA divers could get tanks for 4500 psi years
ago.(smaller physical size for equivalent air volume)

I've been away from diving for a while, so I don't know what the current
systems are using. Guess I'm gonna have to google.

There was a move toward getting European tanks approved for use in the
US, but I don't know how that came out.

9000 psi? Bet that first-stage regulator is something.

--
Bring back, Oh bring back
Oh, bring back that old continuity.
Bring back, oh, bring back
Oh, bring back Clerk Maxwell to me.


Sorry, I was misleading.

My 3000 psi compressor is indeed a scuba compressor. It is very old, heavy,
and military issue. The filters haven't been changed since I've owned it, so
it's probably not safe for breathing. I use it to fill paintball tanks, or
scuba tanks for paintball use only.

When I first got the compressor, I would sometimes use it to fill my 4500
psi tank, but I was getting some pressure blowing past the rings, so I
bought a booster pump. Now I fill my scuba tanks to 3000 with my compressor,
and use the booster to top off the paintball tanks. The booster claims it
will go to 9000 psi, but I've never even heard of a cylinder that could
handle that pressure. The highest I've had it is 4700 psi.