The KingLok adaptors/quick disconnects are compatible with Andale (Snaplok), Lancer Pacific (Fatlock) and other brands of draft beer quick lock fittings that are often seen in commercial pubs and bars.

These check valves are designed to fit liquid lines.

They are made with 5/8 male threads. Depending on what size of gas line you are using you can choose from multiple different hex nut and barbs.

The most common fitting to put on the thread of the back of this fitting is the Duotight 8mm female to 5/8" female push in fitting which you can see here.  Alternatively you can use the hex nut, barbtail and a 5/8" seal and then use a hose clamp.  If you wanted to use these fittings then you will need the 5/8" hex nut, then you can attach one of these tailpieces along with a 5/8" seal:

Angle tailpiece - To suit 4-6mm ID Tubing
Straight tailpiece - To suit 4-6mm ID Tubing
Straight tailpiece - To suit 6-8mm ID Tubing
Straight tailpiece - To suit 8-10mm ID Tubing
Straight tailpiece - To suit 10-13mm ID Tubing

Reducing bush - 5/8 to 1/2 inch MBSP

Kinglok O-ring.