I've found
this link to a manufacturers site. Can't speak Italian so can't translate it...
"Il primo stadio F5 è il più piccolo riduttore di pressione a pistone al mondo. Completamente in ottone cromato con due uscite di bassa pressione contrapposte 3/8”-24UNF e attacco DIN 200 bar. Disponibile in versione ARGON o per miscele ossigeno-arricchite. "
Although I don't understand a word of it, I do see 3/8"-24UNF, which is the thread of a LP port, no mention of any other thread sizes, so I think they might not have a HP port? Meaning that the 2 ports on there are LP ones...
Although you only need one LP port (you can get a "T" and fit a OPV on the opposite arm to the hose. =hose=T=opv= )