The brassie created by Ken Chandler, Doug Davenport, and Gene Lynch of Colorado in the 1960s. With wire for the body and that peacock herl that trout cannot resist. It will handle fast water and deep pools. Depending on size and color it imitates midges and Caddis larva. This fly is a great go-to fly and works anywhere there are Midges and Caddis. You can use this by itself with or without an indicator, a double dropper setup as the anchor or the dropper with or without a strike indicator. Depending on daylight size of hook and size of fish 5X to 7X  tapered leader and tippet are great choices.