Bobbins are the critical tool in tying since they must keep smooth tension on the thread spool and have super smooth inserts to apply the thread to your fly. To this end, Dr. Slick has created a bobbin that handles these tasks with ease. Features delrin feet for smooth tension on the thread spool and has dual ceramic funnel inserts for smooth application of thread to fly. These funnel shaped inserts allow for a smoother application of thread as the bobbin is rotated and they cause less breakage than traditional pipe or straight edged inserts. 4"