Cebora Astro Power Mig Italian Flowmeter Plastic Tube Fitting

[MrCreosote]

The Astro comes with a tiny Italian flow gage that has a quick disconnect fitting for the ~4mm white plastic tube gas line that comes from the welder.

I'd like to get another of these fittings OR would consider midding in a 5/8-18 Inert Gas fitting in the back of the welder.

This OE quick disconnect also has a straight thread and a flat plastic washer gasket at the bottom of the threaded portion.
So even if I found one of these quick disconnect fittings, I would still have to adapt this straight thread to the 5/8-18.

If I could just identify this thread, I could search for an adapter. So far I have not been able to dig up a pic of this ubiquitous Italian regulator of the past.

Here are a couple pics: one of the regulator where you can see the threads and white plastic washer and one of the quick disconnect fitting.

 

[Mart63]

Looks like the connector for a bowden tube on a 3D printer.

 

[Dutch Welder]

As this is low pressure you could use a Festo or Parker 5/8 male to 4mm push in connector.
Maybe you would need a male 5/8 to female 1/4 reducing bush, as most suppliers for 4mm push in connectors have 1/4 threads as the largest.