Fluorocarbon leaders can be engineered with a varying degree of suppleness, rated ST1 to ST5, to perfectly match the fishing style and prevailing conditions. A fluorocarbon line with an ST1 rating is designed to offer maximum stiffness, providing excellent sensitivity and optimal control for precision casting and hook-setting. At the other end of the spectrum a fluorocarbon line with an ST5 rating is engineered for maximum flexibility, allowing for increased knot strength and durability. Whether you need a stiff fluorocarbon line for finesse presentations or a supple line for improved handling, our range of lines with different ST ratings has you covered. W6 ST3 FLUOROCARBON delivers maximum impact and knot strength, all with a small diameter. Fast-sinking line that gets you in the "strike zone" quicker - and with a lower refractive index than monofilament line, it is significantly less visible underwater. W6 ST3 fluorocarbon is offered in diameters from 0.14mm to 1.20mm. Fast sinking Exceptional knot and tensile strength 100% Fluorocarbon Medium stifness High knot strength