Smooth Thread Application: Funnel-shaped glass or ceramic inserts allow for seamless application of thread or other materials as the bobbin is rotated. Delrin Feet: Engineered with delrin feet to maintain smooth tension on the thread spool. Dual Inserts: Available with either dual glass or ceramic inserts to suit your preference. Precision Craftsmanship: Meticulously designed and constructed for optimal performance in tying flies. Versatile Tool: An essential accessory for fly tying enthusiasts and professionals alike.