being a jig manufacturer, as far as I'm concerned, this book is THE bible for advanced Steelhead fishermen, I have the book and read it years ago,(and still reffer to it) which helped me in creating some of the very effective patterns that I currently offer.
I'm sorry I dont know much about the filter system, I just use the information in the book as it is written, and the results have been great.
I didn't have alot of time on the river this winter, I did fish some, and couldn't pick the prime days when the fishing was good, but knowing what, and how Steelhead see, helped me find atleast one Steelhead every trip, and a few multiple fish days, all from the bank with jigs during adverse conditions,(too high, too low & clear) I know that without a doubt,if I didnt have the information in this excellent book, my catch rates wouldn't have even been close. if you havent read the book, buy it, and read it. it will help you put more fish on the bank, and dispell alot of myths, and wives tales, that fishermen have long thought to be true.

Fuzzy

Silent Approach Jigs