Product review (4 stars): Combined with Spray Tube part# 4171544, my dishwasher is back in action!
We have a whirlpool dishwasher that was missing the upper tube and manifold so the top rack of dishes weren't getting cleaned very well and overall, they weren't being rinsed well enough (still had a soapy taste)

After digging around on whirlpool's website, I found that I needed this manifold piece which attaches to the other end of the tube (Part 4171566) and seals at the top water spout.  This allows the water to pump into that top rack cleaning nozzle.

The only thing I couldn't find was the bracket that holds the tube/manifold up.  Once installed onto the nozzle assembly, it will want to droop down from the weight and not make contact with the water spout.  A zip tie holding the tube onto the top rack took care of this (though I'd obviously have preferred to have the actual bracket) but if it works, it works.

Not surprised to see this as a common part used with several different model/brand dishwashers.

Overall it's exactly what I needed to get the job done but for what it is, it's a little on the expensive side :/