Scientific Anglers Nylon Freshwater Tippet. Take this as a mea culpa. For years, SA's leader and tippet materials were marketed and advertised as being something they weren't. The diameters, breaking strengths, and performances just weren't accurate""or up to par with their own rigorous standards. They needed to fix that. Over the past two years, they've meticulously researched, tested, and developed what they believe are the best leaders and tippets ever produced. The new nylon and fluorocarbon materials are, simply put, the strongest and most reliable SA has ever created, with the highest knot strength of anything tested. Period. These breaking strengths and diameters have been put to the test more times than a lab rat, and are finally in line with SA's exacting demands. The bottom line is this: You can fish the other stuff, or you can FISH THE TRUTH.