Review on Joywayus Connectors Adapters Couplers Conditioning by Bobby Lawson

I think I bought these as a 'lucky accident' my R-134a set and thought they would be threaded onto hose ends. Different threads but not lost all because I can use them with my old R-12 set. no need" and they would be right except if someone switched back to R-12 and had R-134a fittings, pressure difference between them and with R-410. So now I don't have to unplug R-134a adapter fittings to get R- $12 to check 12 or R-410 etc. It took me more gas to get them back.