Job Site Gas Quick-Release, Female Plug to Male

The QDB33 has a very nice, smooth connect / disconnect function. However, Western Enterprise's site indicates that this unit also employs a reverse-flow check valve. It does not. Gas flow is not restricted opposite of the flow direction indicated on it's body. At least the two of mine that I received do not. I purchased these primarily to provide reverse-flow protection between two tanks, one Argon, one C25, both connected through one Y-valve so that I could mix the gases when I required lower CO2 levels. I am quite disappointed. Another one of Western Enterprise's part description mistakes I suppose.