Magic Tool CDC Caddis by Larry Conrad.
Hook size 16 fly hook
4 CDC feathers
Wrap 2/3rd of shank of hook with one CDC feather and tie off.
Using magic Tool make a dubbing brush with the fibers of the other three CDC feathers.
Wrap dubbing brush around the upper third of the hook shank with each wrap pull the fibers up to the top of the hook.
Tie off thread and cement threads.
Turn hook over in vise and trim fibers on the bottom of the fly.