Yes there are 2 choices when you plumb a Hiniker.

One choice is to run 2 - 3/8" lines from the manifold to the cooler and then 1/2" lines to 2 knives.

With this setup there will only be 1 line to each knife.

The other choice is to run 1 or 2 restriced lines to the cooler from the manifold.

These restrictors will be rather small.

The restrictors go in the inlet port of the cooler.

The outlet lines then go to the knives as a second line.

This second option is actually a better setup for maximum cooling.

The second setup is probably only needed in cool weather.