Seaguar Tatsu is the world's only double-structure fluorocarbon mainline delivering amazingly strong, yet supple performance Ideal for freshwater multi-species fishing applications - fish can't see it and it's very soft and sensitive. Easy to manage on a reel Our exclusive double-structure process fuses two 100% fluorocarbon resins into one solid line that offers the best combination of strength & castability Soft, supple and smooth casting with exceptional sensitivity, low memory, virtually no stretch, fast sinking and superior knot strength for unmatched performance-in most any conditions Only Seaguar makes its own fluorocarbon resins — exclusively formulated to assure optimum performance