The small diameter ceramic no-wear tube and removable vinyl grip on the standard model of this fly tying tool allows intricate work with fine thread on the smallest to large hooks. Features a solid brass arm and a click drag adjustment to regulate the thread tension. The standard model has a range of 1 to 9 oz. tension and the mag model has a range of 2 to 16 oz. Like an auto mechanics torsion wrench (before the days of air-driven wrenches), this bobbin takes the guesswork out of winding thread, and all but eliminates broken thread at the same time.