Ok, I just spent 1 hour to get them out. What a fight!
The main part is a rubber tube that inserts from the top of the hood. It snaps in place with a recess in the rubber that grips the round metal hole.
Below the hood is a plastic connector that fits in the underside of the rubber part.
At the top is a metal cap that can be pried off; it retains a small metal ball that is the actual jet opening. It's ball shape allows it to rotate inside the rubber part that fits snugly around it.
I am not sure if my rubber part is still water tight, as I gently tried to pry it out with 1 blunt screwdrivers, it has some nicks in the rubber which also acts as a conduit, so I hope I didn't poke through it.
The plastic part actually has a logo on it: SWF.
Anyone knows if this is original?