The Western Inert Gas Quick-Connects allow you to quickly connect/disconnect from your regulator or backpurge device. Sold as the QDB33 for the quick connection from the regulator or QDB34 as a quick connect from hose to hose. I personally have my entire welding shop outfitted with these quality, made in USA quick connects.
B Size, 5/8"-18 RH UNF Thread 200 psi max working pressure
QDB33- Regulator to hose with check valve
QDB34- Hose to machine/hose to hose with check valve