I have tooTMC regulator with selenoid
and there is cga 320
and if You wanna fitt on Fire ext. then need first sruw on with wrench very slow and off many times, then clean all threads from all small steel particles if present , then with ptf plumbers tape at least 20 times(profesionally) wraping around and then with wrench very slowly at Your own risk scruw on.
I personaly once used fire ext., later found pub bottle refill station, i got for refundable on rent 30 pounds 7lb bottle and refill cost 10 pounds and on this bottle need just little wrap tape, very good pass threads .
All at Your own risk
CGA 320 is American standard and pub bottle in UK is more suitable for use 😉
In CGA 320 is same thread as European standart but different thread angle, difference in 5 degrees only.
Bottles with cga320 in UK use Paintbolists, if You have near paintball club, You can ask refill or new one full bottle.
And advice for free 😉 - when scruwed on, open fire ext. and open needle valve then close nedle valve , then close gas from fire ext. for some hours and if presure don't drops then all is ok, also You can check leak or not with shaving foam.
P.S. I will sell my empty standart high quality aluminium bottle for this thread 750gr Co2 Hold, also suitable for Paintball if some body interested PM.
Cheers