I don't have the photo handy--but I want to know what these are called. On each of my calspas pumps (2" side discharge on 4hp pumps, look like this.

you can see in that photo there are multiple attachment sites for (approx) 1/4" tubing. one has to use a drill to open up the hole if one uses one of these sites--they open into the high pressure side of the pump and in my spa were hooked to tubing that eventually ran to the venturi controls.

what are these? do they shoot out water (looked like it to me because of the previous effort to seal them in place (cinched metal band and blue glue))? does air come in thru here via venturi effect?

I did something stupid today and impulsively bought a couple of new wet ends that were "close enough" because they were in stock, but these wet ends do not have these hose attachment points, though I can fabricate them by attaching hose to one of the drain ports...

They're balance hoses designed to prevent/eliminate air locks. And they can't connect to any air line....

That makes sense--much of the tub's plumbing is not accessible so I have been making (often wildly wrong) guesses about where/how things appear to be hooked up. The tubing was connected such that both pumps were connected to what then was probably the interior of the hot tub--I was completely depressed but now I think I will move on, ha ha.

Thanks for the quick and knowledgeable reply!