This ia a pattern from the book "Tying flies with Jack Dennis and Friends". This particular pattern is one by Jay Buchner. I have met and visited with Jay several times and he is an expert tyer who ties some very unique fly patterns. I choose this fly primarily because it is a very easy pattern to tie with limited materials. Can crank out 51 of these in no time. It is a real good caddis pattern and unique due to the CDC feathers. They state in the book "that this CDC Caddis is tied to imitate an adult, but may be taken as a captive emerger or spent caddis because it rides in the surface of the film".