Tie Fast Nail Knot Tying ToolThe Tie Fast Tool helps you tie nail knots which are most commonly used for tying new leaders onto fly lines or tying your backing onto a new fly line. It can be used for a variety of applications, but those are the most common uses for this tool. It is a must have piece of gear. This video will show you how to tie your fly line onto your backing, or tie a new leader on. There are lots of good "how to's" on this video.