If you are tying larger flies, or especially those that have longer shanks like streamers and saltwater flies, the CerMag offers you the additional length you need. And often times, these flies require heavier, tougher thread--which is why Rite Bobbin has built a heavier duty frame with a longer reach, full thread tension control, and a high-quality ceramic tube insert to help you avoid cutting thread due to extreme wear and tear. The durability and length of the CerMag will keep you cranking out those hefty patterns all year long.