Whoops sorry for the double post.....
I did a quick search and didn't find anything so I posted the info.
Beth....Just in case the other thread doesn't clear things up... what the device does is switch one input (one pump) to 8 different outputs in a sequence (I believe that there are 3 different sequences available)
There is a center portion that is for lack of a better description shaped like a donut with holes going through the side as well. water comes in the center and exits out a hole or multiple holes on the side.
It rotates in the center of a block that has chanels machined in to it that direct the flow from the center rotating peice to outputs. As it rotates it lines up with different outputs so it will switch the flow from one input to 8 different outputs.
The 4-way is just a scaled down version of the 8 way. (4 outputs instead of 8)
I hope that this helps....If not... check out the Picture link below they show the device in action.
http://www.oceansmotions.com/feb6.htm
Joel