The Renzetti Dubbing Twister/Teaser. Constructed of a hexagonal brass handle with a round fine toothed rasp on one end and a small shepherd's crook the other. Or you can buy a single function tool with either the rasp or the crook. These tools are used for "spinning-loop dubbing" and the small rasp is used for roughening the texture of the dubbed body. Works on all sizes of flies.