Oh man, I get it now. As long as the fins are sweeping back and coming down across either opening. The water
flows around the bottom and the ramp
squeezes it out the other opening.
Just have to make sure it sweeps down across the inlet and up across the outlet. Either direction will do with the proper connection.
Seems like this means my Jabsco
would do the same, as it's a virtually identical design. That's why I found the thread interesting in the first place.