Scientific Anglers Premium Nylon Leaders - It's all well and good to have a quality fly line, but without a good leader, you're out of luck. Our nylon Freshwater leaders come in four different lengths and feature a longer, larger butt section for easy turnover. These new materials feature the highest wet knot strength in the industry and true-to-spec X sizes. Each leader comes in a two-pack, so you spend less time rooting through your vest for a new leader and more time actually fishing. You can fish the other stuff, or you can Fish the Truth.