Rio Fluoroflex Trout Knotless 9ft Leader RIO's Fluoroflex trout leaders are made of 100% fluorocarbon, and are the perfect solution for when a nearly invisible presentation is required in clear water and for spooky fish. Each leader has high abrasion resistance and excellent tensile and knot strength, and have a long butt section that will turn over flies effortlessly. Each leader is 9ft long, and available in 8 sizes from 7X (1.5lb) to 0X (10lb).