The most often asked for thread sizes?
Brass Adapter (on One Way Valve): 1/4 inch NPT-O2
Emergency Valve Outlet: 9/16 -18 inch UNF 2A (USA “standard scuba”)
Small LP Ports 3/8 inch-24 UNF 2B
Large LP Ports 1/2 inch -20 UNF 2A
The most often asked for thread sizes?