Was thinking of retro fitting them with something more common but if I was to sell the car I’d have to re fit the oem fittings and then I’d be needling the factory coupler anyway.
The car is a RS5
This is the closest I can get to it
This is the factory coupler
To me it’s some kind of fluid line
The system it self is designed and made by KYB
Originally the name was APA KYB which that trade mark has been out of date for some time now.
KYB is a hydraulic company that also go by the name of Kayaba
Here is a photo of the accumulator for the RS4
I suspect that this is a obsolete fitting that they had at the time for KYB hydraulics.
This is not found in any other job and all my years in the HVAC industry I have never seen this fitting.
It’s a a automotive fitting or a known commercial one.
Was hoping that this might be something in the truck industry. Have seen similar fittings for truck suspension.