What are these hubs?

Something I haven't seen, having a hard time figuring this one out.
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Not in the USA as I see it.

 

Maybe some hose to regulate the tire pressure while driving

 

They seem to be mostly used on Brazilian medium duty trucks from the 70s. They are on the back too. Apparently they are made for dodges too, I've seen a d-950 with them.

 

Central tire inflation system while driving often seen on Aussie Road Trains .

 

Thank you! That makes so much sense, I didn't think inflation systems ever used a ridgid air line like that. Looks cool when they go over bumps, the hub cams down.