LOL!
Somehow, I KNEW that was going to be your next question!
O.K.,...The front one way is called a one way, because of the two one way bearings in it. One for each side, or wheel. Each one way bearing will drive in one direction, but freewheel in the other, which is why brakes don't work, and reverse, too.
The center one way pulley has only one, one way bearing in it, but performs the same function, and allows whatever is mounted in front of it, whether a standard differential, spool or one way, to act as they were intended, but in forward mode only. This is why I say the center one way is redundant, when combined with a front one way. You still get forward drive, but the front one way is already performing it's duties, and still has that same forward drive/rear freewheel effect, so the center one way is just an extra function that is not needed, but doesn't negatively affect anything else, otherwise.
Confusing, but once you get the idea of how each component works, not that hard to grasp.