394 Fly Tying Tool Bobbin Holder Bullet Head Spooled Arc Mouth Stainless #394 New Manufacturer: n/a Condition: Very Good Part Number: Stainless Steel Construction. This Fly-Tying Bobbin Holder is made of polished stainless steel, which is strong, durable and smooth without harming the thread. Brass Bullet Head. Bullet Head Bobbin Holder maintain constant tension on the thread, so you can make the perfect flies without disruption. Well Balanced of Tension and Smoothness. The beveled and polished tip allows your thread to easily flow through and prevents your thread from fraying or breaking as you are tying your flies. For All Thread Spools. The bobbin is adjustable for all of your thread spools and will accept varying different sizes making your fly tying easier and more fun. Time-saving Fly Tying Tool. The Bobbin Holder will make it much easier for you to tie your flies so you can easily thread your bobbin.