The Rite Bobbins cross-shaped pressure disc adjusts for just the right tension for any particular tying job. Click drag adjustment provides from 1 to 9 oz. of thread tension on standard model, 2 - 16 oz. of thread tension on Cermag bobbins. Ceramic thread tubes in standard and Cermag models protect fine thread. Larger bore long tubes make big, bulky flies easier to tie. Cermag models have long-reach thread tubes. Half Hitch model has a tapered barrel and O-ring grip that allows you to whip finish right on the barrel. Available:Cermag, Standard, Half Hitch. Cancer and Reproductive Harm- www.P65Warnings.ca.gov. Type: Bobbins.